ci: global GOFLAGS with -mod=vendor

.circleci/config.yml

@@ -1,5 +1,9 @@
 version: 2
 
+env-shared: &env-shared
+  environment:
+    GOFLAGS: "-mod=vendor"
+
 build-shared: &build-shared
   steps:
     - checkout
@@ -16,12 +20,12 @@ build-shared: &build-shared
     - run:
         name: Run tests
         command: |
-          go test -v -mod=vendor ./...
+          go test -v ./...
     - run:
         name: Compile project on every platform
         command: |
           go get github.com/mitchellh/gox
-          GOFLAGS=-mod=vendor gox -parallel 10 -os "linux freebsd" -osarch "darwin/i386 darwin/amd64"
+          gox -parallel 10 -os "linux freebsd" -osarch "darwin/i386 darwin/amd64"
     - save_cache:
         key: pkg-cache-{{ checksum "go.sum" }}-v5
         paths:
@@ -29,14 +33,17 @@ build-shared: &build-shared
 
 jobs:
   "golang:1.12":
+    <<: *env-shared
     <<: *build-shared
     docker:
       - image: circleci/golang:1.12
   "golang:latest":
+    <<: *env-shared
     <<: *build-shared
     docker:
       - image: circleci/golang:latest
   release:
+    <<: *env-shared
     docker:
       - image: circleci/golang:1.12
     steps: