Standardize Build

The build now uses spring build conventions to simplify the build

Fixes gh-4284

samples/boot/insecure/spring-security-samples-boot-insecure.gradle

@@ -0,0 +1,8 @@
+apply plugin: 'io.spring.convention.spring-sample-boot'
+
+dependencies {
+	compile 'org.springframework.boot:spring-boot-starter-thymeleaf'
+	compile 'org.springframework.boot:spring-boot-starter-web'
+
+	testCompile 'org.springframework.boot:spring-boot-starter-test'
+}