add gcc required to build with newer version of go

Author: yannh

.gitlab-ci.yml

@@ -5,7 +5,7 @@ stages:
   - build
 
 before_script:
-  - apk add --no-cache make git
+  - apk add --no-cache make git gcc
   - mkdir -p /go/src/github.com/yannh
   - cp -r $CI_PROJECT_DIR /go/src/github.com/yannh/redis-dump-go
   - cd /go/src/github.com/yannh/redis-dump-go