feat: Create provisioner abstraction (#12)

* feat: Create provisioner abstraction

Creates a provisioner abstraction that takes prior art from the Terraform plugin system. It's safe to assume this code will change a lot when it becomes integrated with provisionerd.

Closes #10.

* Ignore generated files in diff view

* Check for unstaged file changes

* Install protoc-gen-go

* Use proper drpc plugin version

* Fix serve closed pipe

* Install sqlc with curl for speed

* Fix install command

* Format CI action

* Add linguist-generated and closed pipe test

* Cleanup code from comments

* Add dRPC comment

* Add Terraform installer for cross-platform

* Build provisioner tests on Linux only

Makefile

@@ -3,11 +3,11 @@ database/dump.sql: $(wildcard database/migrations/*.sql)
 	go run database/dump/main.go
 
 # Generates Go code for querying the database.
-.PHONY: database/generate
 database/generate: database/dump.sql database/query.sql
 	cd database && sqlc generate && rm db_tmp.go
 	cd database && gofmt -w -r 'Querier -> querier' *.go
 	cd database && gofmt -w -r 'Queries -> sqlQuerier' *.go
+.PHONY: database/generate
 
 fmt/prettier:
 	@echo "--- prettier"
@@ -21,3 +21,16 @@ endif
 
 fmt: fmt/prettier
 .PHONY: fmt
+
+gen: database/generate provisionersdk/proto
+.PHONY: gen
+
+# Generates the protocol files.
+provisionersdk/proto: provisionersdk/proto/provisioner.proto
+	cd provisionersdk/proto && protoc \
+		--go_out=. \
+		--go_opt=paths=source_relative \
+		--go-drpc_out=. \
+		--go-drpc_opt=paths=source_relative \
+		./provisioner.proto
+.PHONY: provisionersdk/proto