Add integration with travis-ci and coveralls

Added integration with travis-ci and badges for travis and coveralls

.travis.yml

@@ -0,0 +1,13 @@
+language: go
+go:
+  - 1.2
+  - 1.3
+  - 1.4
+
+install:
+  - go get github.com/axw/gocov/gocov
+  - go get github.com/mattn/goveralls
+  - if ! go get code.google.com/p/go.tools/cmd/cover; then go get golang.org/x/tools/cmd/cover; fi
+  - go get github.com/stretchr/testify/assert
+script:
+  - $HOME/gopath/bin/goveralls -service=travis-ci

README.md

@@ -1,5 +1,9 @@
 # goback
 [![GoDoc](https://godoc.org/github.com/carlescere/goback?status.svg)](https://godoc.org/github.com/carlescere/goback)
+[![Build Status](https://travis-ci.org/carlescere/goback.svg)](https://travis-ci.org/carlescere/goback)
+[![Coverage Status](https://coveralls.io/repos/carlescere/goback/badge.svg)](https://coveralls.io/r/carlescere/goback)
+
+
 Goback implements a simple exponential backoff.
 
 An exponential backoff approach is typically used when treating with potentially faulty/slow systems. If a system fails quick retries may exacerbate the system specially when the system is dealing with several clients. In this case a backoff provides the faulty system enough room to recover.