ref(Dockerfile): remove deprecated --strip-vcs flag

This behavior is the default in current versions of glide.

Author: mboersma

Dockerfile

@@ -9,7 +9,7 @@ COPY glide.lock /go/src/github.com/deis/controller-sdk-go/
 
 WORKDIR /go/src/github.com/deis/controller-sdk-go
 
-RUN glide install --strip-vcs --strip-vendor
+RUN glide install --strip-vendor
 
 COPY ./_scripts /usr/local/bin