Update whitespace in Dockerfile

Signed-off-by: Alex Ellis (OpenFaaS Ltd) <alexellis2@gmail.com>

gateway/Dockerfile

@@ -32,10 +32,8 @@ COPY scaling        scaling
 COPY pkg            pkg
 COPY main.go        .
 
-
 RUN license-check -path ./ --verbose=false "Alex Ellis" "OpenFaaS Authors" "OpenFaaS Author(s)"
 
-
 # Run a gofmt and exclude all vendored code.
 RUN test -z "$(gofmt -l $(find . -type f -name '*.go' -not -path "./vendor/*"))"
 RUN go test $(go list ./... | grep -v integration | grep -v /vendor/ | grep -v /template/) -cover