functional tests

Крыгин Иван
Коммит сделал вчера, но почему то pull request не сделался
```
Traceback (most recent call last):
  File "./run_tests.py", line 5, in <module>
    from tests.tests import Test
  File "/Users/bayandin/repos/tech-testing-ha2/tests/tests.py", line 4, in <module>
    from constants import Credentials
  File "/Users/bayandin/repos/tech-testing-ha2/constants.py", line 6, in <module>
    class Credentials(object):
  File "/Users/bayandin/repos/tech-testing-ha2/constants.py", line 7, in Credentials
    TTHA2LOGIN = os.environ['TTHA2LOGIN']
  File "/usr/local/Cellar/python/2.7.8_2/Frameworks/Python.framework/Versions/2.7/lib/python2.7/UserDict.py", line 23, in __getitem__
    raise KeyError(key)
KeyError: 'TTHA2LOGIN'
```