Use tox-travis for test builds on TravisCI, update tox.ini accordingly

.travis.yml

@@ -1,6 +1,4 @@
 sudo: required
-language: python
-
 services:
   - docker
 before_script:
@@ -12,12 +10,14 @@ after_script:
 notifications:
   email: false
 install:
-  - pip install tox
+  - pip install tox-travis
 cache: pip
 
+language: python
+python:
+  - "2.7"
+  - "3.4"
+  - "3.5"
+  - "3.6"
 script:
-  - tox -e py27
-  - tox -e py34
-  - tox -e py35
-  - tox -e py36
-  - tox -e flake8
+  - tox

requirements-dev.txt

@@ -1,3 +1,4 @@
+pytest
 pep8
 codecov
 python-dotenv

tox.ini

@@ -1,13 +1,31 @@
 [tox]
-envlist = py{27,34,35,36}, flake8
-skip_missing_interpreters = true
+envlist = py{27,34,35,36},flake8
 
 [testenv]
-deps = pytest
-       python-dotenv
-commands = py.test {posargs}
-passenv = VCAP_SERVICES
+commands = py.test -v
+deps = -r{toxinidir}/requirements-dev.txt
+passenv =
+    TRAVIS
+    TRAVIS_BRANCH
+    TRAVIS_JOB_ID
+    VCAP_SERVICES
 
 [testenv:flake8]
+commands = flake8 .
 deps = flake8
-commands = flake8 .
+
+[travis]
+python =
+  3.6: py36, flake8
+
+[pytest]
+addopts = --ignore=setup.py
+python_files = *.py
+python_functions = test_
+
+[flake8]
+exclude =
+    .git,
+    .tox,
+    build,
+    dist