Try to parallelize linting

.travis.yml

@@ -1,32 +1,35 @@
 dist: xenial
-
 os:
 - linux
-
 language: go
-
-go:
-- "1.14.x"
-- tip
-
-matrix:
-  allow_failures:
-  - go: tip
-
-cache:
-  directories:
-    - $GOPATH/pkg/mod
-
-env:
-- GOLANGCI_RELEASE="v1.26.0"
-
-before_install:
-- GO111MODULE=off go get github.com/mattn/goveralls
-- GO111MODULE=off go get github.com/lawrencewoodman/roveralls
-- curl -sfL https://install.goreleaser.com/github.com/golangci/golangci-lint.sh | sh -s -- -b $(go env GOPATH)/bin ${GOLANGCI_RELEASE}
-
-script:
-- make test
-- make lint
-- travis_wait 20 roveralls
-- goveralls -coverprofile=roveralls.coverprofile -service=travis-ci
+jobs:
+  include:
+  - stage: common
+
+    go:
+    - "1.14.x"
+    - tip
+
+    matrix:
+      allow_failures:
+      - go: tip
+
+    cache:
+      directories:
+        - $GOPATH/pkg/mod
+
+    env:
+    - GOLANGCI_RELEASE="v1.26.0"
+
+    before_install:
+    - GO111MODULE=off go get github.com/mattn/goveralls
+    - GO111MODULE=off go get github.com/lawrencewoodman/roveralls
+
+    script:
+    - make test
+    - travis_wait 20 roveralls
+    - goveralls -coverprofile=roveralls.coverprofile -service=travis-ci
+  - before_install:
+    - curl -sfL https://install.goreleaser.com/github.com/golangci/golangci-lint.sh | sh -s -- -b $(go env GOPATH)/bin ${GOLANGCI_RELEASE}
+    script:
+    - make lint