allow use of hyphens in project name
allow use of hyphens in project name

Summary:
## Motivation (required)

Allows the use of hyphens in the project name.

## Test Plan (required)

The updated CLI successfully generates projects.

This should resolve #99.
Closes https://github.com/facebook/react-vr/pull/109

Reviewed By: amberroy

Differential Revision: D4931463

Pulled By: andrewimm

fbshipit-source-id: bd07be3

ichengde/react-vr,ichengde/react-vr