update drone ci.

Dockerfile

@@ -1,6 +1,6 @@
 ## 1. Build Server
-# Use Go 1.12
-FROM golang:1.12 AS build-server
+# Use Go 1.14
+FROM golang:1.14 AS build-server
 
 # Load repository into docker
 WORKDIR /project/
@@ -15,7 +15,7 @@ RUN go build -installsuffix cgo -ldflags="-s -w" -o /binaries/rpdata-server ./cm
 
 ## 2. Distribute
 # Use alpine linux
-FROM alpine:3.7
+FROM alpine:3.12
 
 # Install certificates to enable HTTPS GET requests, and tzdata for log imports.
 RUN apk add --no-cache ca-certificates tzdata