Update the CI versions of go and alpine

.drone.yml

@@ -17,7 +17,6 @@ steps:
 - name: backend
   image: golang:1.14.0-alpine3.11
   commands:
-  - apk --no-cache add git
   - GO111MODULE=off go get -tags 'postgres' -u github.com/golang-migrate/migrate/cmd/migrate
   - cp $$GOPATH/bin/migrate migrate
   - CGO_ENABLED=0 go build -ldflags '-extldflags "-static"' -trimpath -v -o canapeapp/app backend/*.go
@@ -25,6 +24,7 @@ steps:
 - name: prepare-docker
   image: alpine:3.11.3
   commands:
+  - apk --no-cache add git
   - cp docker/run.sh canapeapp/run.sh
   - cp migrate canapeapp/migrate
   - cp -R migrations canapeapp/migrations