add tests, new engine

- add `should throw if error and you can '.catch' it` test for jade and octet, and change a little bit other tests.
This test case is when you call some locals from template that not exists (not provided) in locals object.
- change mocha version, because of `customFds` deprication
- remove `--reporter spec` (you know why, lol), because it is default in newest versions.

this should be according to the template anyways: https://github.com/jshttp/style-guide/blob/master/template/package.json#L25-L29