most of vmware-archive#80 (took Dockerfile, Makefile and go.mod)

* Use go .12 and use modules instead of dep
* Use a multistage Dockerfile to build/test the project
* Updated the versions of:
  * Go: v1.9 -> v1.12.x
  * Alpine Linux: v3.6 -> v3.9.
  * Go dependencies, for example: k8s.io/client_go v5.0.0 -> v12.0.0
* version to 0.3 (from 0.2)

Signed-off-by: Vigith Maurice <vigith@gmail.com>

Author: vigith

Dockerfile

@@ -11,13 +11,21 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+FROM golang:1.12.9 AS build
 
-FROM alpine:3.4
 MAINTAINER Timothy St. Clair "tstclair@heptio.com"  
+WORKDIR /src/
+COPY . .
 
+RUN CGO_ENABLED=0 go build -o /src/eventrouter
+
+FROM alpine:3.9 as release
+
+WORKDIR /app
 RUN apk update --no-cache && apk add ca-certificates
-ADD eventrouter /eventrouter 
+COPY --from=build /src/eventrouter .
 USER nobody:nobody
 
-CMD ["/bin/sh", "-c", "/eventrouter -v 3 -logtostderr"]
+ENTRYPOINT [ "./eventrouter" ]
+CMD ["-v", "3", "-logtostderr"]