Introduce initial Hydro CLI architecture (#390)

* wip

* wip

* wip

* wip

* Parallel service init and stdout capture

* Simplify Python interface

* Polish

* Update design doc for new deployment API

* Capture stderr as well

* Add API for getting exit code

* Initial logic for configuring ports

* Break out into several modules

* Set up infrastructure for provisioning with Terraform

.gitignore

@@ -1,3 +1,4 @@
 /target*
 /rust.git
-/*.dot
+/*.dot
+__pycache__/