explicit matrix

Author: willmcgugan

.travis.yml

@@ -21,7 +21,16 @@ matrix:
     - python: "3.7"
       env:
         - SETUPTOOLS=setuptools PIP=pip
+    - python: "3.5"
+      os: osx
+      env:
+        - SETUPTOOLS=setuptools PIP=pip
+    - python: "3.6"
+      os: osx
+      env:
+        - SETUPTOOLS=setuptools PIP=pip
     - python: "3.7"
+      os: osx
       env:
         - SETUPTOOLS=setuptools PIP=pip
 
@@ -40,7 +49,3 @@ after_success:
 # command to run tests
 script:
   - nosetests -v --with-coverage --cover-package=fs tests
-
-os:
-  - linux
-  - osx