feat: add goproxy

Author: appleboy

.drone.yml

@@ -2,14 +2,15 @@ kind: pipeline
 name: lint
 
 clone:
-  depth: 50
+  depth: 1
 
 steps:
 - name: testing
   image: golang:1.12
   pull: true
   environment:
     GO111MODULE: on
+    GOPROXY: https://proxy.golang.org
   commands:
   - make vet
   - make lint
@@ -26,14 +27,15 @@ kind: pipeline
 name: testing
 
 clone:
-  depth: 50
+  depth: 1
 
 steps:
 - name: testing
   image: golang:1.12
   pull: true
   environment:
     GO111MODULE: on
+    GOPROXY: https://proxy.golang.org
   commands:
   - make test