update travis config to only test the correct python env. Replace codecov with coveralls

.travis.yml

@@ -8,9 +8,7 @@ python:
   - "3.7"
 
 env:
-  - TOX_ENV=py36-django-20
-  - TOX_ENV=py35-django-20
-  - TOX_ENV=py37-django-20
+  - DJANGO_VERSION=django-20
 
 matrix:
   fast_finish: true
@@ -19,7 +17,7 @@ matrix:
 install: pip install -r requirements_test.txt
 
 # command to run tests using coverage, e.g. python setup.py test
-script: tox -e $TOX_ENV
+script: tox -e $(echo py$TRAVIS_PYTHON_VERSION-$DJANGO_VERSION | tr -d .)
 
 after_success:
-  - codecov -e TOX_ENV
+  - coveralls

README.rst

@@ -8,8 +8,8 @@ Django-Cryptolock
 .. image:: https://travis-ci.org/dethos/django-cryptolock.svg?branch=master
     :target: https://travis-ci.org/dethos/django-cryptolock
 
-.. image:: https://codecov.io/gh/dethos/django-cryptolock/branch/master/graph/badge.svg
-    :target: https://codecov.io/gh/dethos/django-cryptolock
+.. image:: https://coveralls.io/repos/github/dethos/django-cryptolock/badge.svg
+    :target: https://coveralls.io/github/dethos/django-cryptolock
 
 Django authentication using cryptocurrency wallets
 

requirements_test.txt

@@ -2,7 +2,7 @@ coverage==4.4.1
 mock>=1.0.1
 flake8>=2.1.0
 tox>=1.7.0
-codecov>=2.0.0
+coveralls
 django-model-utils>=2.0
 
 # Additional test requirements go here