Adds Terraform fmt/validate via GitHub Actions

.github/workflows/terraform.yml

@@ -0,0 +1,20 @@
+name: 'Terraform GitHub Actions'
+on:
+  - pull_request
+jobs:
+  terraform:
+    name: 'Terraform'
+    runs-on: ubuntu-latest
+    steps:
+      - name: 'Checkout'
+        uses: actions/checkout@master
+      - name: 'Terraform Format'
+        uses: hashicorp/terraform-github-actions@master
+        with:
+          tf_actions_version: 0.12.13
+          tf_actions_subcommand: 'fmt'
+      - name: 'Terraform Validate'
+        uses: hashicorp/terraform-github-actions@master
+        with:
+          tf_actions_version: 0.12.13
+          tf_actions_subcommand: 'validate'