add vendoring with go dep

vendor/github.com/davecgh/go-spew/.travis.yml

@@ -0,0 +1,14 @@
+language: go
+go:
+    - 1.5.4
+    - 1.6.3
+    - 1.7
+install:
+    - go get -v golang.org/x/tools/cmd/cover
+script:
+    - go test -v -tags=safe ./spew
+    - go test -v -tags=testcgo ./spew -covermode=count -coverprofile=profile.cov
+after_success:
+    - go get -v github.com/mattn/goveralls
+    - export PATH=$PATH:$HOME/gopath/bin
+    - goveralls -coverprofile=profile.cov -service=travis-ci