- all tests translated to mocha
- split in server and client tests
- solution for the problem that a server has to run for client tests (done before,
  after functions)
- add destroy server to README
- add 3 devel dependencies (I really hope thats ok)
- add 3 commands:

npm run cover
npm run mocha
npm test

runs both
Commented out server test for now because it conflicted with client test (it didn't like running both at the same time on my machine)
Minor code style changes