Added arm, arm64 and windows dockerfiles
Changes to dockerfile should reduce size
Update to readme for extra badges (same as drone-plugins)
Should just need to uncomment and fix tags to auto-publish to docker hub
Add 'parallelism' parameter to limit the number of concurrent operations as Terraform walks its graph.
Download glibc-2.21-r2.apk from 'github.com/sgerrand/alpine-pkg-glibc' as 'circle-artifacts.com/gh/andyshinn/alpine-pkg-glibc' is not available.
Correct 'terraform apply' with parallelism option.
Run 'go fmt'.