unit tests

Signed-off-by: Casey Lee <cplee@nektos.com>

pkg/runner/testdata/actions/docker-local/Dockerfile

@@ -0,0 +1,8 @@
+# Container image that runs your code
+FROM alpine:3.10
+
+# Copies your code file from your action repository to the filesystem path `/` of the container
+COPY entrypoint.sh /entrypoint.sh
+
+# Code file to execute when the docker container starts up (`entrypoint.sh`)
+ENTRYPOINT ["/entrypoint.sh"]