Integration tests

[c4s4]

In order to check that code works as expected, I have coded integration tests using Venom. To run them:

$ cd examples
$ go test

Tests are in files examples/test/.yml* and are quite self explanatory:

request:
  url: "{{.URL}}/noModel"
  method: GET
response:
  statusCode: 200
  json: null

request entry describes request and response describes assertions made on response.

Note that these tests pass on master branch but fail on dev. Adding them would be a great way to check automatically that everything works fine.