Migrate dep to vgo.

.circleci/config.yml

@@ -1,7 +1,6 @@
 version: 2
 jobs:
   test:
-    working_directory: /go/src/github.com/yukimochi/Activity-Relay
     docker:
       - image: circleci/golang
         environment:
@@ -13,8 +12,6 @@ jobs:
           name: build
           command: |
             go version
-            go get -u github.com/golang/dep/cmd/dep
-            dep ensure
             go test -coverprofile=coverage.txt -covermode=atomic -p 1 . ./worker ./cli ./State
             bash <(curl -s https://codecov.io/bash)
   docker: