Fix published POMs

This commit removes the dependencyManagement section from the published
POMs and aligns the starter dependencies with the official ones.

build.gradle

@@ -27,6 +27,9 @@ subprojects {
 		dependencies {
 			dependency 'com.graphql-java:graphql-java:15.0'
 		}
+		generatedPomCustomization {
+			enabled = false
+		}
 	}
 
 	dependencies {

spring-boot-starter-graphql-web/build.gradle

@@ -2,5 +2,6 @@ description = "Starter for building GraphQL Java applications with Spring MVC"
 
 dependencies {
     api project(':spring-graphql-web')
+	api 'org.springframework.boot:spring-boot-starter'
     api 'org.springframework.boot:spring-boot-starter-web'
 }

spring-boot-starter-graphql-webflux/build.gradle

@@ -2,5 +2,6 @@ description = "Starter for building GraphQL Java applications with Spring WebFlu
 
 dependencies {
     api project(':spring-graphql-web')
+	api 'org.springframework.boot:spring-boot-starter'
     api 'org.springframework.boot:spring-boot-starter-webflux'
 }