Add "go test" to drone suite

.drone.yml

@@ -2,6 +2,13 @@ kind: pipeline
 name: default
 
 steps:
+  - name: test_draftbot
+    image: golang
+    commands:
+      - cd ./draftbot
+      - GOPROXY=https://modules.fromouter.space go mod download
+      - CGO_ENABLED=0 go test .
+
   - name: build_draftbot
     image: golang
     commands: