update travis to test more go versions to ensure compatibility

* 172ad49 do not fetch linters and vet for go 1.1 tests

.travis.yml

@@ -1,5 +1,7 @@
 language: go
 go:
+  - 1.1
+  - 1.2
   - 1.3
   - 1.4
   - release
@@ -7,8 +9,8 @@ go:
 
 script:
   # linters and vet
-  - go get golang.org/x/tools/cmd/vet
-  - go get github.com/golang/lint/golint
+  - (go version | grep "go1.1") || go get golang.org/x/tools/cmd/vet
+  - (go version | grep "go1.1") || go get github.com/golang/lint/golint
 
   # pull all external dependencies
   - go get github.com/cucumber/gherkin-go