strict dependencies in setup.py

Author: LD250

.travis.yml

@@ -4,7 +4,7 @@ python:
     - "3.4"
     - "3.5"
 install:
-    pip install flake8
+    - pip install flake8 mock==1.3.0
 script:
     - flake8 .
     - python setup.py test

setup.py

@@ -14,9 +14,9 @@
 else:
     raise RuntimeError('Unable to find version string.')
 
-requires = ['pbr>=1.6.0',
-            'python-jenkins>=0.4.8',
-            'six>=1.9.0']
+requires = ['pbr==1.6.0',
+            'python-jenkins==0.4.8',
+            'six==1.9.0']
 
 tests_require = ['unittest2==1.1.0',
                  'mock==1.3.0',