Delete sample Gradle builds

Remove the Gradle builds that were provided with some of the sample
applications since they were never directly invoked.

See gh-9316

spring-boot-samples/spring-boot-sample-actuator/build.gradle

-buildscript {
-	ext {
-		springBootVersion = '2.0.0.BUILD-SNAPSHOT'
-	}
-	repositories {
-		// NOTE: You should declare only repositories that you need here
-		mavenLocal()
-		mavenCentral()
-		maven { url "http://repo.spring.io/release" }
-		maven { url "http://repo.spring.io/milestone" }
-		maven { url "http://repo.spring.io/snapshot" }
-	}
-	dependencies {
-		classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
-	}
-}
-
-apply plugin: 'java'
-apply plugin: 'eclipse'
-apply plugin: 'idea'
-apply plugin: 'org.springframework.boot'
-apply plugin: 'io.spring.dependency-management'
-
-group = 'org.springframework.boot'
-version = springBootVersion
-
-repositories {
-	// NOTE: You should declare only repositories that you need here
-	mavenLocal()
-	mavenCentral()
-	maven { url "http://repo.spring.io/release" }
-	maven { url "http://repo.spring.io/milestone" }
-	maven { url "http://repo.spring.io/snapshot" }
-}
-
-dependencies {
-	compile("org.springframework.boot:spring-boot-starter-actuator")
-	compile("org.springframework.boot:spring-boot-starter-jdbc")
-	compile("org.springframework.boot:spring-boot-starter-security")
-	compile("org.springframework.boot:spring-boot-starter-web")
-	runtime("com.h2database:h2")
-
-	compileOnly('org.springframework.boot:spring-boot-configuration-processor')
-
-	testCompile("org.springframework.boot:spring-boot-starter-test")
-}
-
-springBoot {
-	buildInfo()
-}

spring-boot-samples/spring-boot-sample-logback/build.gradle

-buildscript {
-	ext {
-		springBootVersion = '2.0.0.BUILD-SNAPSHOT'
-	}
-	repositories {
-		// NOTE: You should declare only repositories that you need here
-		mavenLocal()
-		mavenCentral()
-		maven { url "http://repo.spring.io/release" }
-		maven { url "http://repo.spring.io/milestone" }
-		maven { url "http://repo.spring.io/snapshot" }
-	}
-	dependencies {
-		classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
-	}
-}
-
-apply plugin: 'java'
-apply plugin: 'eclipse'
-apply plugin: 'idea'
-apply plugin: 'org.springframework.boot'
-apply plugin: 'io.spring.dependency-management'
-
-version = springBootVersion
-group = 'org.springframework.boot'
-
-repositories {
-	// NOTE: You should declare only repositories that you need here
-	mavenLocal()
-	mavenCentral()
-	maven { url "http://repo.spring.io/release" }
-	maven { url "http://repo.spring.io/milestone" }
-	maven { url "http://repo.spring.io/snapshot" }
-}
-
-dependencies {
-	compile("org.springframework.boot:spring-boot-starter")
-	testCompile("org.springframework.boot:spring-boot-starter-test")
-}
\ No newline at end of file

spring-boot-samples/spring-boot-sample-profile/build.gradle

-buildscript {
-	ext {
-		springBootVersion = '2.0.0.BUILD-SNAPSHOT'
-	}
-	repositories {
-		// NOTE: You should declare only repositories that you need here
-		mavenLocal()
-		mavenCentral()
-		maven { url "http://repo.spring.io/release" }
-		maven { url "http://repo.spring.io/milestone" }
-		maven { url "http://repo.spring.io/snapshot" }
-	}
-	dependencies {
-		classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
-	}
-}
-
-apply plugin: 'java'
-apply plugin: 'eclipse'
-apply plugin: 'idea'
-apply plugin: 'org.springframework.boot'
-apply plugin: 'io.spring.dependency-management'
-
-version = springBootVersion
-group = 'org.springframework.boot'
-
-repositories {
-	// NOTE: You should declare only repositories that you need here
-	mavenLocal()
-	mavenCentral()
-	maven { url "http://repo.spring.io/release" }
-	maven { url "http://repo.spring.io/milestone" }
-	maven { url "http://repo.spring.io/snapshot" }
-}
-
-dependencies {
-	compile("org.springframework.boot:spring-boot-starter")
-	testCompile("org.springframework.boot:spring-boot-starter-test")
-}
\ No newline at end of file

spring-boot-samples/spring-boot-sample-simple/build.gradle

-buildscript {
-	ext {
-		springBootVersion = '2.0.0.BUILD-SNAPSHOT'
-	}
-	repositories {
-		// NOTE: You should declare only repositories that you need here
-		mavenLocal()
-		mavenCentral()
-		maven { url "http://repo.spring.io/release" }
-		maven { url "http://repo.spring.io/milestone" }
-		maven { url "http://repo.spring.io/snapshot" }
-	}
-	dependencies {
-		classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
-	}
-}
-
-apply plugin: 'java'
-apply plugin: 'eclipse'
-apply plugin: 'idea'
-apply plugin: 'org.springframework.boot'
-apply plugin: 'io.spring.dependency-management'
-
-version = springBootVersion
-group = 'org.springframework.boot'
-
-repositories {
-	// NOTE: You should declare only repositories that you need here
-	mavenLocal()
-	mavenCentral()
-	maven { url "http://repo.spring.io/release" }
-	maven { url "http://repo.spring.io/milestone" }
-	maven { url "http://repo.spring.io/snapshot" }
-}
-
-dependencies {
-	compile("org.springframework.boot:spring-boot-starter")
-	compile("org.hibernate:hibernate-validator")
-	testCompile("org.springframework.boot:spring-boot-starter-test")
-}

spring-boot-samples/spring-boot-sample-web-static/build.gradle

-buildscript {
-	ext {
-		springBootVersion = '2.0.0.BUILD-SNAPSHOT'
-	}
-	repositories {
-		// NOTE: You should declare only repositories that you need here
-		mavenLocal()
-		mavenCentral()
-		maven { url "http://repo.spring.io/release" }
-		maven { url "http://repo.spring.io/milestone" }
-		maven { url "http://repo.spring.io/snapshot" }
-	}
-	dependencies {
-		classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
-	}
-}
-
-apply plugin: 'org.springframework.boot'
-apply plugin: 'io.spring.dependency-management'
-apply plugin: 'war'
-
-version = springBootVersion
-group = 'org.springframework.boot'
-
-repositories {
-	// NOTE: You should declare only repositories that you need here
-	mavenLocal()
-	mavenCentral()
-	maven { url "http://repo.spring.io/release" }
-	maven { url "http://repo.spring.io/milestone" }
-	maven { url "http://repo.spring.io/snapshot" }
-}
-
-dependencies {
-	compile("org.springframework.boot:spring-boot-starter-web")
-	compile("org.webjars:bootstrap:3.0.3")
-	compile("org.webjars:jquery:2.0.3-1")
-	providedRuntime("org.springframework.boot:spring-boot-starter-tomcat")
-	testCompile("org.springframework.boot:spring-boot-starter-test")
-}

spring-boot-samples/spring-boot-sample-web-ui/build.gradle

-buildscript {
-	ext {
-		springBootVersion = '2.0.0.BUILD-SNAPSHOT'
-	}
-	repositories {
-		// NOTE: You should declare only repositories that you need here
-		mavenLocal()
-		mavenCentral()
-		maven { url "http://repo.spring.io/release" }
-		maven { url "http://repo.spring.io/milestone" }
-		maven { url "http://repo.spring.io/snapshot" }
-	}
-	dependencies {
-		classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
-	}
-}
-
-apply plugin: 'java'
-apply plugin: 'org.springframework.boot'
-apply plugin: 'io.spring.dependency-management'
-
-version = springBootVersion
-
-repositories {
-	// NOTE: You should declare only repositories that you need here
-	mavenLocal()
-	mavenCentral()
-	maven { url "http://repo.spring.io/release" }
-	maven { url "http://repo.spring.io/milestone" }
-	maven { url "http://repo.spring.io/snapshot" }
-}
-
-dependencies {
-	compile("org.springframework.boot:spring-boot-starter-web")
-	compile("org.springframework.boot:spring-boot-starter-thymeleaf")
-	testCompile("org.springframework.boot:spring-boot-starter-test")
-}