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>

circle.yml

@@ -6,15 +6,17 @@ machine:
 
 dependencies:
   pre:
-    - go generate
-    - CGO_ENABLED=0 go build -a -installsuffix nocgo .
-    - go get github.com/mitchellh/gox
     - go get github.com/tcnksm/ghr
-    - gox -verbose -os "linux darwin windows" --output "dist/{{.Dir}}_{{.OS}}_{{.Arch}}"
-
+    - make validate
   override:
+    - make binary
+
+test:
+  override:
+    - make test
+  post:
     - echo $REPO
-    - docker build -t ${REPO,,} .
+    - make image
 
 deployment:
   github:
@@ -24,4 +26,4 @@ deployment:
       - docker login -e $DOCKER_EMAIL -u $DOCKER_USER -p $DOCKER_PASS
       - docker push ${REPO,,}:latest
       - docker tag ${REPO,,}:latest ${REPO,,}:$CIRCLE_SHA1
-      - docker push ${REPO,,}:$CIRCLE_SHA1
+      - docker push ${REPO,,}:$CIRCLE_SHA1