Fixed python3 deprecation warnings in test.py

When running with `Python3.3.3` lines 17, 22, 26, 30 and 35 are triggering this warning:
```python
test.py:N: DeprecationWarning: Please use assertEqual instead.
````

After this fix the tests still pass cleanly under `Python 2.7.6`, but I get this:
```python
..../usr/lib64/python3.3/unittest/case.py:384: ResourceWarning: unclosed file <_io.BufferedReader name='.../flask_heroku/static/robots.txt'>
  function()
.
```
which I am guessing is an issue with flask or unittest.