add support for 'reuse' mode to allow act to be used for a fast local task runner

.github/actions/check/Dockerfile

@@ -1,10 +1,6 @@
-FROM golang:1.11.4-stretch
-
-RUN go get -u honnef.co/go/tools/cmd/staticcheck
-RUN go get -u golang.org/x/lint/golint
-RUN go get -u github.com/fzipp/gocyclo
+FROM golangci/golangci-lint:v1.12.5
 
 COPY "entrypoint.sh" "/entrypoint.sh"
 RUN chmod +x /entrypoint.sh
 
-ENTRYPOINT ["/entrypoint.sh"]
+ENTRYPOINT ["/entrypoint.sh"]