Update Makefile

to @go install ./cmd/mapstructure-to-hcl2 so that we can `make generate` and tests that generated code is what it should be

Makefile

@@ -53,6 +53,7 @@ install-gen-deps: ## Install dependencies for code generation
 	@(cd $(TEMPDIR) && GO111MODULE=on go get github.com/mna/pigeon@master)
 	@(cd $(TEMPDIR) && GO111MODULE=on go get github.com/alvaroloes/enumer@master)
 	@go install ./cmd/struct-markdown
+	@go install ./cmd/mapstructure-to-hcl2
 
 dev: ## Build and install a development build
 	@grep 'const VersionPrerelease = ""' version/version.go > /dev/null ; if [ $$? -eq 0 ]; then \
@@ -97,6 +98,8 @@ fmt-examples:
 generate: install-gen-deps ## Generate dynamically generated code
 	@echo "==> removing autogenerated markdown..."
 	@find website/source/ -type f | xargs grep -l '^<!-- Code generated' | xargs rm
+	@echo "==> removing autogenerated code..."
+	@find find post-processor common helper template builder provisioner -type f | xargs grep -l '^// Code generated' | xargs rm
 	go generate ./...
 	go fmt common/bootcommand/boot_command.go
 	go fmt command/plugin.go