[minor] Default makers to generate in src/

[kbond]

• Add --test option to generate in tests/

Questions:

1. Should --test be interactive?
2. Should the folders be plural (current) or singular? src/Stories or src/Story, src/Factories or src/Factory. Mostly, it seems the standard is singular (with the exception of Migrations).

[weaverryan]

Should --test be interactive?

I don't mind interactive questions. But in this case, in either direction, it could get kinda annoying once you've generated your 5th thing. When --test is NOT passed, we could print a message on top:

// pass --test if you want to generate files into your tests/ directory

Longer-term, you could envision a config option to default which one you want

Should the folders be plural (current) or singular? src/Stories or src/Story, src/Factories or src/Factory.

Probably singular??? :)