add gcc to dockerfile: cgo doesn't work without it

Author: jirfag

Dockerfile

@@ -1,3 +1,6 @@
-FROM scratch
-COPY golangci-lint /
-ENTRYPOINT ["/golangci-lint"]
+FROM golang:1.10
+
+RUN apt-get update && apt-get install -y gcc
+
+COPY golangci-lint $GOPATH/bin/
+ENTRYPOINT ["golangci-lint"]