Python 3 unit test fix

- Fix unit test for get_map on Python 3 by specifying 'byte' data type
  (also improved alignment and removed superfluous parentheses)
- Add Python 3.5 build job on Travis to check for issues with Python 3

Author: laymonage

.travis.yml

@@ -1,6 +1,7 @@
 language: python
 python:
   - "2.7"
+  - "3.5"
 install: 
   - pip install -r requirements.txt
   - pip install python-coveralls

tests/test.py

@@ -56,8 +56,8 @@ def test_get_map(self):
         """Tests the get_map method"""
         map_file = os.path.join(os.getcwd(), 'markdown.png')
         data = self.loklak.get_map(17.582729, 79.118320)
-        self.assertTrue(data[:8] == '\211PNG\r\n\032\n' and
-                                    (data[12:16] == 'IHDR'))
+        self.assertTrue(data[:8] == b'\211PNG\r\n\032\n' and
+                        data[12:16] == b'IHDR')
         with open(map_file, 'wb') as file_handle:
             file_handle.write(data)
         with open(map_file, 'rb') as file_handle: