fix dockerfile

Dockerfile

@@ -9,7 +9,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-FROM scratch
+FROM alpine
+ARG BUILT_ARTIFACT
 ADD "$BUILT_ARTIFACT" /
 EXPOSE 8080
-ENTRYPOINT /giteainterceptor
+ENTRYPOINT [ "/giteainterceptor" ]
+CMD [ ]