enable codecov summary

Author: spacewander

.travis.yml

@@ -1,7 +1,10 @@
 language: go
 
 script:
-  - go test -args -alhoc
+  - go test -covermode count -coverprofile coverage.txt -args -alhoc
+after_success:
+  # See https://github.com/codecov/example-go
+  - bash <(curl -s https://codecov.io/bash)
 
 go:
   - 1.6