Added support for template and assets overriding

Dockerfile

@@ -6,8 +6,9 @@ RUN apk --no-cache --no-progress add --virtual \
   linux-pam-dev
 
 WORKDIR /gogs.io/gogs
-COPY . .
-RUN make build-no-gen TAGS="cert pam"
+COPY . .  
+RUN  go get -u github.com/kevinburke/go-bindata/...
+RUN make build TAGS="cert pam"
 
 FROM alpine:3.11
 ADD https://github.com/tianon/gosu/releases/download/1.11/gosu-amd64 /usr/sbin/gosu