Re-instate vendor directory

vendor/github.com/hpcloud/tail/Dockerfile

@@ -0,0 +1,19 @@
+FROM golang
+
+RUN mkdir -p $GOPATH/src/github.com/hpcloud/tail/
+ADD . $GOPATH/src/github.com/hpcloud/tail/
+
+# expecting to fetch dependencies successfully.
+RUN go get -v github.com/hpcloud/tail
+
+# expecting to run the test successfully.
+RUN go test -v github.com/hpcloud/tail
+
+# expecting to install successfully
+RUN go install -v github.com/hpcloud/tail
+RUN go install -v github.com/hpcloud/tail/cmd/gotail
+
+RUN $GOPATH/bin/gotail -h || true
+
+ENV PATH $GOPATH/bin:$PATH
+CMD ["gotail"]