Fix RFC822 filters + More tests (#257)

* Make rfc822 filters compatible with Windows systems.

.strftime() is relative to the system it's being run on.
UNIX has '%s' for seconds since the EPOCH, Windows doesn't (ValueError).
Solution: use .timestamp() to achieve the same result on both platforms.
This also allows us to drop the float() around it, since it returns a float.

* Start testing filters

* Add placeholders for more tests

* Make 'tests' folder a Python package

Now you can run tests with just `pytest tests`

* Update readme and travis config

* Test timesince()

* Update and organize .gitignore

Deleted: (nothing)
Added: Coverage files, .idea\

* Test filter_truthy, category_name

* Tests for backend.py

* Tests for bencode.py

* Move (empty) test_models.py to tests package

* Tests for utils.py

* Fixes for flattenDict

* Change name to `flatten_dict`
* `newkey` was assigned but never used

* Add a helper class for testing

* Show coverage on Travis

(only Travis for now...)

* Remove IDE

* Use correct assert functions

* Update README.md

tests/test_backend.py

@@ -0,0 +1,46 @@
+import unittest
+
+from nyaa import backend
+
+
+class TestBackend(unittest.TestCase):
+
+    # def setUp(self):
+    #     self.db, nyaa.app.config['DATABASE'] = tempfile.mkstemp()
+    #     nyaa.app.config['TESTING'] = True
+    #     self.app = nyaa.app.test_client()
+    #     with nyaa.app.app_context():
+    #         nyaa.db.create_all()
+    #
+    # def tearDown(self):
+    #     os.close(self.db)
+    #     os.unlink(nyaa.app.config['DATABASE'])
+
+    def test_replace_utf8_values(self):
+        test_dict = {
+            'hash': '2346ad27d7568ba9896f1b7da6b5991251debdf2',
+            'title.utf-8': '¡hola! ¿qué tal?',
+            'filelist.utf-8': [
+                'Español 101.mkv',
+                'ру́сский 202.mp4'
+            ]
+        }
+        expected_dict = {
+            'hash': '2346ad27d7568ba9896f1b7da6b5991251debdf2',
+            'title': '¡hola! ¿qué tal?',
+            'filelist': [
+                'Español 101.mkv',
+                'ру́сский 202.mp4'
+            ]
+        }
+
+        self.assertTrue(backend._replace_utf8_values(test_dict))
+        self.assertDictEqual(test_dict, expected_dict)
+
+    @unittest.skip('Not yet implemented')
+    def test_handle_torrent_upload(self):
+        pass
+
+
+if __name__ == '__main__':
+    unittest.main()