Fixes #2

[ehhc]

I've also added the gradle wrapper files so that a new user don't has to download and install gradle...

[Pentadrago]

Thank you for the pull request.
This commit contains two changes I don't agree with:

1. The idea plugin is disliked by the Jetbrains People because it uses the old and somehow deprecated configuration format. I'd like to keep IDE stuff from this project and rely on the import functions of the IDEs.
2. Why did you delete the WarInitializer? This enabled the deployment onto an app server.
   Best regards,
   Steven

[ehhc]

Regarding your second question: i've deleted it since it (resp. the used interface) is deprecated in the newer spring versions (cf. https://stackoverflow.com/questions/38843015/spring-boot-springbootservletinitializer-is-deprecated).

But you're correct mentioning that i should have looked for a solution working with the newer spring version instead of deleting it altogether