Add tests for Python 3.7-dev (#11)

* Test for python 3.7-dev

* py37

Author: Danielhiversen

.travis.yml

@@ -10,6 +10,8 @@ matrix:
     env: TOXENV=py36
   - python: "nightly"
     env: TOXENV=py37
+  - python: "3.7-dev"
+    env: TOXENV=py37
 
   - python: '3.5'
     env: TOXENV=lint

tox.ini

@@ -1,13 +1,13 @@
 [tox]
-envlist = py34, py35, py36, lint
+envlist = py34, py35, py36, py37, lint
 skip_missing_interpreters = True
 
 [testenv]
 setenv =
     LANG=en_US.UTF-8
     PYTHONPATH = {toxinidir}:{toxinidir}/Tibber
 commands = 
-   - pip install flake8 pylint gql aiohttp==2.2.5 async_timeout==1.4.0 pytest tox coveralls pytest-cov
+   - pip install flake8 pylint gql aiohttp==2.2.5 async_timeout==1.4.0 pytest pytest-cov
    - py.test --cov --cov-report= {posargs} test/test.py