Update build toolchain to the use of docker…

… for integration tests.

- Update circle.yml to start the docker daemon listening on TCP (to be
  able to talk to it from the container running test-integration)
- Update script/test-integration to prepare the use of go-check
- Update Makefile in order to run less "binary" target and setting up
  the right environment variable for the builds

Signed-off-by: Vincent Demeester <vincent@sbr.pm>

build.Dockerfile

@@ -4,10 +4,26 @@ RUN go get github.com/tools/godep
 RUN go get github.com/mitchellh/gox
 RUN go get github.com/tcnksm/ghr
 
+# Which docker version to test on
+ENV DOCKER_VERSION 1.6.2
+
+# Download docker
+RUN set -ex; \
+    curl https://get.docker.com/builds/Linux/x86_64/docker-${DOCKER_VERSION} -o /usr/local/bin/docker-${DOCKER_VERSION}; \
+    chmod +x /usr/local/bin/docker-${DOCKER_VERSION}
+
+# Set the default Docker to be run
+RUN ln -s /usr/local/bin/docker-${DOCKER_VERSION} /usr/local/bin/docker
+
 ENV PATH /go/src/github.com/emilevauge/traefik/Godeps/_workspace/bin:$PATH
 
 WORKDIR /go/src/github.com/emilevauge/traefik
 
+# This is a hack (see libcompose#32) - will be removed when libcompose will be fixed
+# (i.e go get able)
+RUN mkdir -p /go/src/github.com/docker/docker/autogen/dockerversion/
+COPY Godeps/_workspace/src/github.com/docker/docker/autogen/dockerversion/dockerversion.go /go/src/github.com/docker/docker/autogen/dockerversion/dockerversion.go
+
 RUN mkdir Godeps
 COPY Godeps/Godeps.json Godeps/
 RUN godep restore