Added an option to use Rest Assured version 3.0

without this change it's impossible to use Rest Assured 3.0 with Spring Cloud Contract. That's because we are adding Rest Assured 2.0 imports.
with this change we detect Rest Assured version. If 3.0 is available on the classpath we change the imports

fixes #266

docs/src/main/asciidoc/verifier/rest.adoc

@@ -41,6 +41,36 @@ dependencies {
 }
 ----
 
+====== Gradle and Rest Assured 3.0
+
+By default Rest Assured 2.x is added to the classpath. However in order to give the users the
+opportunity to use Rest Assured 3.x it's enough to add it to the plugins classpath.
+
+[source,groovy,indent=0]
+----
+buildscript {
+	repositories {
+		mavenCentral()
+	}
+	dependencies {
+	    classpath "org.springframework.boot:spring-boot-gradle-plugin:${springboot_version}"
+		classpath "org.springframework.cloud:spring-cloud-contract-gradle-plugin:${verifier_version}"
+		classpath "io.rest-assured:rest-assured:3.0.2"
+		classpath "io.rest-assured:spring-mock-mvc:3.0.2"
+	}
+}
+
+depenendencies {
+    // all dependencies
+    // you can exclude rest-assured from spring-cloud-contract-verifier
+    testCompile "io.rest-assured:rest-assured:3.0.2"
+    testCompile "io.rest-assured:spring-mock-mvc:3.0.2"
+}
+----
+
+That way the plugin will automatically see that Rest Assured 3.x is present on the classpath
+and will modify the imports accordingly.
+
 ====== Snapshot versions for Gradle
 
 Add the additional snapshot repository to your build.gradle to use snapshot versions which are automatically uploaded after every successful build:
@@ -277,6 +307,63 @@ include::{standalone_samples_path}/http-server/pom.xml[tags=contract_maven_plugi
 
 You can read more in the https://cloud.spring.io/spring-cloud-contract/spring-cloud-contract-maven-plugin/[Spring Cloud Contract Maven Plugin Docs]
 
+====== Maven and Rest Assured 3.0
+
+By default Rest Assured 2.x is added to the classpath. However in order to give the users the
+opportunity to use Rest Assured 3.x it's enough to add it to the plugins classpath.
+
+[source,groovy,indent=0]
+----
+<plugin>
+    <groupId>org.springframework.cloud</groupId>
+    <artifactId>spring-cloud-contract-maven-plugin</artifactId>
+    <version>${spring-cloud-contract.version}</version>
+    <extensions>true</extensions>
+    <configuration>
+        <packageWithBaseClasses>com.example</packageWithBaseClasses>
+    </configuration>
+    <dependencies>
+        <dependency>
+            <groupId>org.springframework.cloud</groupId>
+            <artifactId>spring-cloud-contract-verifier</artifactId>
+            <version>${spring-cloud-contract.version}</version>
+        </dependency>
+        <dependency>
+           <groupId>io.rest-assured</groupId>
+           <artifactId>rest-assured</artifactId>
+           <version>3.0.2</version>
+           <scope>compile</scope>
+        </dependency>
+        <dependency>
+           <groupId>io.rest-assured</groupId>
+           <artifactId>spring-mock-mvc</artifactId>
+           <version>3.0.2</version>
+           <scope>compile</scope>
+        </dependency>
+    </dependencies>
+</plugin>
+
+<dependencies>
+    <!-- all dependencies -->
+    <!-- you can exclude rest-assured from spring-cloud-contract-verifier -->
+    <dependency>
+       <groupId>io.rest-assured</groupId>
+       <artifactId>rest-assured</artifactId>
+       <version>3.0.2</version>
+       <scope>test</scope>
+    </dependency>
+    <dependency>
+       <groupId>io.rest-assured</groupId>
+       <artifactId>spring-mock-mvc</artifactId>
+       <version>3.0.2</version>
+       <scope>test</scope>
+    </dependency>
+</dependencies>
+----
+
+That way the plugin will automatically see that Rest Assured 3.x is present on the classpath
+and will modify the imports accordingly.
+
 ====== Snapshot versions for Maven
 
 For Snapshot / Milestone versions you have to add the following section to your `pom.xml`