update travis config

Author: slogsdon

.travis.yml

@@ -1,12 +1,8 @@
 language: elixir
-elixir: 1.0.0
-otp_release:
-  - 17.0
-  - 17.1
-  - 17.3
-before_script:
-  - "MIX_ENV=test mix do deps.get, compile"
+elixir:
+  - 1.2
+  - 1.3
+script:
+  - mix test
 after_success:
   - MIX_ENV=test mix coveralls.travis
-  - MIX_ENV=docs mix deps.get
-  - MIX_ENV=docs mix inch.report