Update docker image.

Shrink docker image.
Update from fig (deprecated) to docker-compose.
Update README.md.

Signed-off-by: Tiago Pires <tandrepires@gmail.com>

docker/blocks/docker_gogs/Dockerfile

@@ -1,23 +1,20 @@
-FROM ubuntu:14.04
+FROM buildpack-deps:trusty-scm
 
 # This part is taken from the official docker image --------------------
 
 RUN apt-get update && apt-get install -y \
-		build-essential ca-certificates curl \
-		bzr git mercurial openssh-client\
-		--no-install-recommends
+		build-essential --no-install-recommends
 
 ENV GOLANG_VERSION 1.3
 
-RUN curl -sSL http://golang.org/dl/go$GOLANG_VERSION.src.tar.gz \
-	| tar -v -C /usr/src -xz
-WORKDIR /usr/src/go
+RUN curl -sSL https://golang.org/dl/go$GOLANG_VERSION.src.tar.gz \
+		| tar -v -C /usr/src -xz
 
-RUN cd src && ./make.bash --no-clean 2>&1
+RUN cd /usr/src/go/src && ./make.bash --no-clean 2>&1
 
 ENV PATH /usr/src/go/bin:$PATH
 
-RUN mkdir -p /go/src
+RUN mkdir -p /go/src /go/bin && chmod -R 777 /go
 ENV GOPATH /go
 ENV PATH /go/bin:$PATH
 WORKDIR /go

docker/blocks/docker_gogs_dev/Dockerfile

@@ -1,24 +1,20 @@
-FROM ubuntu:14.04
+FROM buildpack-deps:trusty-scm
 
-# This part is derived from the official docker image ------------------
+# This part is taken from the official docker image --------------------
 
-RUN DEBIAN_FRONTEND=noninteractive apt-get update && \
-		apt-get install -qy \
-		build-essential ca-certificates curl \
-		bzr git mercurial openssh-client\
-		--no-install-recommends
+RUN apt-get update && apt-get install -y \
+		build-essential --no-install-recommends
 
 ENV GOLANG_VERSION 1.3
 
-RUN curl -sSL http://golang.org/dl/go$GOLANG_VERSION.src.tar.gz \
-	| tar -v -C /usr/src -xz
-WORKDIR /usr/src/go
+RUN curl -sSL https://golang.org/dl/go$GOLANG_VERSION.src.tar.gz \
+		| tar -v -C /usr/src -xz
 
-RUN cd src && ./make.bash --no-clean 2>&1
+RUN cd /usr/src/go/src && ./make.bash --no-clean 2>&1
 
 ENV PATH /usr/src/go/bin:$PATH
 
-RUN mkdir -p /go/src
+RUN mkdir -p /go/src /go/bin && chmod -R 777 /go
 ENV GOPATH /go
 ENV PATH /go/bin:$PATH
 WORKDIR /go