Update building stuff

- Add a Makefile with common targets (binary, test, validate, ..)
- Use docker to build it (isolated)

And update circleci to work with the new Makefile..

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

script/test-integration

@@ -0,0 +1,8 @@
+#!/bin/bash
+
+export SCRIPTDIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+export DEST=.
+
+TESTFLAGS="$TESTFLAGS"
+#go test -v ./integration
+