Add SQLite support for easy setup (#336)

* Modifies schema to allow SQLite as a DB driver. SQLite is preinstalled in most OSes allowing for minimal prerequisites in the installation process.

* Removes Redis dependency and replaces "real" redis instance with ioredis-mock this is not feature complete and errors are expected.

* Updates medusa new command to only ask for Postgres credentials if the starter template has database_type === "postgres" in medusa-config.js

* Small improvements to bin resolution

* Improvements to endpoint stability

packages/medusa/.gitignore

@@ -3,4 +3,4 @@ node_modules
 .DS_store
 .env*
 .env
-
+*.sql