Reorganising tests

no issue

- update run notes in casper tests' base.js file
- move casper tests inside of /test/client
- move all remaining unit, functional and integration tests to
  /test/server
- this leaves us with core/test/client/functional/client which is weird,
  but --target=client is useful, can fix this later
- update most of the dev dependencies, except should which has a breaking
  change