Set up gradle for java

[ArchibaldBienetre]

Please check that this is working for you:

You don't need to worry about installing gradle.

To get gradle to download the latest version for you + run the tests, just call: ./gradlew clean test

The output should look something like this for you:

hoobert@newbuntu:~/repos/csv2tex_fork (set-up-gradle-for-java) 
$ ./gradlew clean test
Starting a Gradle Daemon, 3 stopped Daemons could not be reused, use --status for details

BUILD SUCCESSFUL in 3s
4 actionable tasks: 4 executed