feat: run fmt and validate in Drone pipeline

Author: jasonwalsh

.drone.yml

@@ -1,6 +1,12 @@
 kind: pipeline
 name: aws-networking-readonly
 steps:
+  - commands:
+      - terraform fmt -check
+      - terraform init
+      - terraform validate
+    image: hashicorp/terraform:1.0.9
+    name: validate
   - commands:
       - apk add git
       - npm install @semantic-release/changelog -D