Option for PostgreSQL

[metaskills]

Technically Lamby supports any database, it is not in the Lamby gem's scope to care about which Rack framework or potential database you might use with it or not. That said, this cookiecutter project could have an option on which database you would like to get started with to help showcase what we cover in our guides. https://lamby.custominktech.com/docs/database#our-cookiecutter Addressed Lamby issue feedback here:

• Postgresql Support lamby#142

[jeremiahlukus]

I like this idea to add another param to the build step

 [1/2] project_name (my_awesome_lambda): 
 [2/2] database (mysql or postgres): 

After looking in cookiecutter it seems like this is pretty doable.