Unit testing for def/ module.

Added unit tests to test code in def/ module.

vendor/github.com/montanaflynn/stats/.travis.yml

@@ -1,17 +1,13 @@
 language: go
 go:
-  - 1.1
-  - 1.2
-  - 1.3
-  - 1.4
-  - 1.5
-  - tip
+  - stable
+  - master
 before_install:
-  - sudo pip install codecov
+  - go get github.com/mattn/goveralls
 script:
-  - go test
+  - go test -v -covermode=count -coverprofile=coverage.out
 after_success:
-  - codecov
+  - $GOPATH/bin/goveralls -coverprofile=coverage.out -service=travis-ci
 notifications:
   email:
     recipients: