Add verify-gomod and verify-goimports to Travis job

Makefile

@@ -571,7 +571,7 @@ ci: govet verify-gofmt verify-gomod verify-goimports verify-boilerplate verify-b
 #  govet: covered by pull-kops-verify-govet
 #  verify-boilerplate: covered by pull-kops-verify-boilerplate
 .PHONY: travis-ci
-travis-ci: verify-misspelling nodeup examples test | verify-gendocs verify-packages verify-apimachinery
+travis-ci: verify-misspelling verify-gomod verify-goimports nodeup examples test | verify-gendocs verify-packages verify-apimachinery
 	echo "Done!"
 
 .PHONY: pr

go.mod

@@ -120,7 +120,7 @@ require (
 	golang.org/x/crypto v0.0.0-20190510104115-cbcb75029529
 	golang.org/x/net v0.0.0-20190812203447-cdfb69ac37fc
 	golang.org/x/oauth2 v0.0.0-20190402181905-9f3314589c9a
-	golang.org/x/tools v0.0.0-20191124021906-f5828fc9a103 // indirect
+	golang.org/x/tools v0.0.0-20191124021906-f5828fc9a103
 	google.golang.org/api v0.0.0-20181220000619-583d854617af
 	gopkg.in/gcfg.v1 v1.2.0
 	gopkg.in/inf.v0 v0.9.1

hack/verify-goimports

@@ -34,6 +34,16 @@ for package in packages:
     continue
   paths.append(package)
 
+# Install goimports from vendor
+print('installing goimports from vendor')
+
+process = subprocess.Popen(['go', 'install', 'k8s.io/kops/vendor/golang.org/x/tools/cmd/goimports'], stdout=subprocess.PIPE, cwd=path.join(gopath, 'src'))
+stdout, stderr = process.communicate()
+if process.returncode != 0:
+  print("FAIL: installing goimports from vendor failed")
+  print(stderr)
+  sys.exit(1)
+
 print("packages %s" % paths)
 
 env = os.environ

tools.go

@@ -26,6 +26,8 @@ import (
 
 	_ "github.com/client9/misspell/cmd/misspell"
 
+	_ "golang.org/x/tools/cmd/goimports"
+
 	_ "honnef.co/go/tools/cmd/staticcheck"
 
 	_ "sigs.k8s.io/controller-tools/cmd/controller-gen"