Organize tests

During our previous Code Jam we broke the tests, this commit fixes that
and also organizes the test structure, basically what has been done is:

- Standarize rake tasks
- Organize on diferrent folders unit and integration tests
- Separate spec_helper by test levels
- File configuration contains params for different test levels
Merge pull request #11 from jesusmercado/organize_tests

Organize test strucutre