Create new project

[shaunlebron]

Since we are touting this as a beginner's tool that makes leiningen invisible, we need to be able to run lein new mies or some variant to create projects, not just adding existing projects.

[oakmac]

Still a few punchlist items before this is complete:

• [x] put focus on new project input field when going to that step
• [x] press enter on new project input field should work
• [x] input validation of new project folder

[oakmac]

Needs testing on Mac and Windows.

[LesleyMdCampo]

On a Mac: pressing enter and input validation working. I am getting a cursor in the new project input field, but no outline.

[oakmac]

Works on Windows