add gradle commands into readme

README.md

@@ -77,14 +77,21 @@ If you're a developer, you can add your own Ripper by following the wiki guide:
 
 # Compiling & Building
 
-The project uses [Maven](http://maven.apache.org/).
-To build the .jar file using Maven, navigate to the root project directory and run:
+The project uses [Gradle](https://gradle.org) or [Maven](http://maven.apache.org/).
+Therefor both commands are given. To build the .jar file, navigate to the root
+project directory and run:
 
 ```bash
 mvn clean compile assembly:single
+mvn -B package assembly:single -Dmaven.test.skip=true
+```
+```bash
+./gradlew clean build
+./gradlew clean build -x test --warning-mode all
 ```
 
-This will include all dependencies in the JAR.
+This will include all dependencies in the JAR. One can skip executing the tests
+as well.
 
 # Running Tests
 
@@ -98,6 +105,12 @@ mvn test -DexcludedGroups= -Dgroups=flaky,slow
 mvn test '-Dgroups=!slow'
 ```
 
+```bash
+./gradlew test
+./gradlew test -DexcludeTags= -DincludeTags=flaky,slow
+./gradlew test '-DincludeTags=!slow'
+```
+
 Please note that some tests may fail as sites change and our rippers become out of date.
 Start by building and testing a released version of RipMe
 and then ensure that any changes you make do not cause more tests to break.