Added helper methods for contract extension

without these methods to use  and  fields you need to prepend the  word - otherwise you're setting it on the project

fixes #328

spring-cloud-contract-tools/spring-cloud-contract-gradle-plugin/src/main/groovy/org/springframework/cloud/contract/verifier/plugin/ContractVerifierExtension.groovy

@@ -158,6 +158,26 @@ class ContractVerifierExtension {
 		String classifier
 		String version
 		String stringNotation
+
+		void groupId(String groupId) {
+			this.groupId = groupId
+		}
+
+		void artifactId(String artifactId) {
+			this.artifactId = artifactId
+		}
+
+		void classifier(String classifier) {
+			this.classifier = classifier
+		}
+
+		void version(String version) {
+			this.version = version
+		}
+
+		void stringNotation(String stringNotation) {
+			this.stringNotation = stringNotation
+		}
 	}
 
 	static class BaseClassMapping {

spring-cloud-contract-tools/spring-cloud-contract-gradle-plugin/src/test/groovy/org/springframework/cloud/contract/verifier/plugin/GradleContractsDownloaderSpec.groovy

@@ -20,4 +20,50 @@ class GradleContractsDownloaderSpec extends Specification {
 			stubConfig.version == "1.0.0"
 			stubConfig.classifier == "stubs"
 	}
+
+	def "should parse dependency via direct setting"() {
+		given:
+			def dep = new ContractVerifierExtension.Dependency(
+					groupId: "com.example",
+					artifactId: "foo",
+					version: "1.0.0",
+					classifier: "stubs"
+			)
+		when:
+			StubConfiguration stubConfig = new GradleContractsDownloader(null, null).stubConfiguration(dep)
+		then:
+			stubConfig.groupId == "com.example"
+			stubConfig.artifactId == "foo"
+			stubConfig.version == "1.0.0"
+			stubConfig.classifier == "stubs"
+	}
+	def "should parse dependency via string notation with methods"() {
+		given:
+			String stringNotation = "com.example:foo:1.0.0:stubs"
+			def dep = new ContractVerifierExtension.Dependency()
+			dep.stringNotation(stringNotation)
+		when:
+			StubConfiguration stubConfig = new GradleContractsDownloader(null, null).stubConfiguration(dep)
+		then:
+			stubConfig.groupId == "com.example"
+			stubConfig.artifactId == "foo"
+			stubConfig.version == "1.0.0"
+			stubConfig.classifier == "stubs"
+	}
+
+	def "should parse dependency via direct setting with methods"() {
+		given:
+			def dep = new ContractVerifierExtension.Dependency()
+			dep.groupId("com.example")
+			dep.artifactId("foo")
+			dep.version("1.0.0")
+			dep.classifier("stubs")
+		when:
+			StubConfiguration stubConfig = new GradleContractsDownloader(null, null).stubConfiguration(dep)
+		then:
+			stubConfig.groupId == "com.example"
+			stubConfig.artifactId == "foo"
+			stubConfig.version == "1.0.0"
+			stubConfig.classifier == "stubs"
+	}
 }