Vendor 0.12 SDK (#3432)

```bash
GO111MODULE=on go get github.com/hashicorp/[email protected]
GO111MODULE=on go mod vendor
GO111MODULE=on go mod tidy
```

go.mod

@@ -1,48 +1,24 @@
 module github.com/terraform-providers/terraform-provider-google
 
 require (
-	cloud.google.com/go v0.34.0
+	cloud.google.com/go v0.36.0
 	github.com/apparentlymart/go-cidr v1.0.0
-	github.com/aws/aws-sdk-go v1.16.24 // indirect
-	github.com/blang/semver v3.5.1+incompatible // indirect
 	github.com/davecgh/go-spew v1.1.1
 	github.com/dustinkirkland/golang-petname v0.0.0-20170921220637-d3c2ba80e75e // indirect
 	github.com/gammazero/deque v0.0.0-20180920172122-f6adf94963e4 // indirect
 	github.com/gammazero/workerpool v0.0.0-20181230203049-86a96b5d5d92
-	github.com/golang/snappy v0.0.0-20180518054509-2e65f85255db // indirect
-	github.com/google/btree v0.0.0-20180813153112-4030bb1f1f0c // indirect
-	github.com/googleapis/gax-go v2.0.2+incompatible // indirect
 	github.com/hashicorp/errwrap v1.0.0
 	github.com/hashicorp/go-cleanhttp v0.5.0
-	github.com/hashicorp/go-getter v1.0.1 // indirect
-	github.com/hashicorp/go-hclog v0.0.0-20181001195459-61d530d6c27f // indirect
 	github.com/hashicorp/go-multierror v1.0.0
-	github.com/hashicorp/go-plugin v0.0.0-20181212150838-f444068e8f5a // indirect
-	github.com/hashicorp/go-uuid v1.0.0 // indirect
 	github.com/hashicorp/go-version v1.1.0
 	github.com/hashicorp/hcl v1.0.0 // indirect
-	github.com/hashicorp/hcl2 v0.0.0-20181215005721-253da47fd604 // indirect
-	github.com/hashicorp/hil v0.0.0-20170627220502-fa9f258a9250 // indirect
-	github.com/hashicorp/logutils v1.0.0 // indirect
-	github.com/hashicorp/terraform v0.11.9-0.20180926212128-35d82b055591
+	github.com/hashicorp/terraform v0.12.0-alpha4.0.20190410234817-9e158400c228
 	github.com/hashicorp/vault v1.0.1 // indirect
 	github.com/keybase/go-crypto v0.0.0-20181127160227-255a5089e85a // indirect
-	github.com/mitchellh/cli v1.0.0 // indirect
-	github.com/mitchellh/copystructure v1.0.0 // indirect
 	github.com/mitchellh/hashstructure v1.0.0
-	github.com/mitchellh/mapstructure v1.1.2 // indirect
 	github.com/pierrec/lz4 v2.0.5+incompatible // indirect
 	github.com/stoewer/go-strcase v1.0.2
-	github.com/stretchr/testify v1.3.0 // indirect
 	github.com/terraform-providers/terraform-provider-random v2.0.0+incompatible
-	github.com/zclconf/go-cty v0.0.0-20181218225846-4fe1e489ee06 // indirect
-	go.opencensus.io v0.18.0 // indirect
-	golang.org/x/crypto v0.0.0-20181203042331-505ab145d0a9 // indirect
-	golang.org/x/net v0.0.0-20190119204137-ed066c81e75e // indirect
-	golang.org/x/oauth2 v0.0.0-20181203162652-d668ce993890
-	golang.org/x/sys v0.0.0-20190123074212-c6b37f3e9285 // indirect
-	google.golang.org/api v0.0.0-20181217000635-41dc4b66e69d
-	google.golang.org/appengine v1.3.0 // indirect
-	google.golang.org/genproto v0.0.0-20181218023534-67d6565462c5 // indirect
-	google.golang.org/grpc v1.17.0 // indirect
+	golang.org/x/oauth2 v0.0.0-20190220154721-9b3c75971fc9
+	google.golang.org/api v0.1.0
 )