Try to fix the broken Travis CI build

.travis.yml

@@ -7,11 +7,10 @@ python:
   - "pypy"
 install:
   - "pip install -U setuptools pip"
-  - "pip install pytest pytest-cov pytest-pep8 mock responses coveralls"
+  - "pip install pytest>=3.6 pytest-cov pytest-pep8 mock responses coveralls"
   - "pip install ."
 script: "py.test"
 after_success: "coveralls"
 branches:
   only:
     - master
-    - develop

README.rst

@@ -12,7 +12,7 @@ your application. It is based on the official client docker-py_.
 
 The document is in ReadTheDocs_.
 
-.. _ReadTheDocs: https://flask-docker.readthedocs.org
+.. _ReadTheDocs: https://flask-docker.readthedocs.io
 
 
 Installation

tox.ini

@@ -8,7 +8,7 @@ setenv =
     LANG=C.UTF-8
 deps =
     setuptools>=12.0
-    pytest
+    pytest>=3.6
     pytest-cov
     pytest-pep8
     mock