use random ids for directory names

[johrstrom]

We should use random ids for directory names so that when the students get into 'extra credit land' (i.e., they're done with the base project) they can easily create a feature to rename projects.

In fact, creating a project (in step 2 or 3?) should

• create a random string for the directory name
• write a .info file in json with the name in it

So that when the students get into 'extra credit land' they have the infrastructure ready to be able to rename projects.