Generate sample data to insert into tables

[TerenceSperringerJr]

After completing #1,

Generate the following sample data to insert into tables:

• [x] 100 users
• [x] 200 friendships
• [x] 10 groups
• [x] 300 messages

[TerenceSperringerJr]

• [x] Messages can only come from other friends.

[TerenceSperringerJr]

• [x] User IDs must start at 1 (not 0)

[TerenceSperringerJr]

• [ ] group limit might be optional(?) or required...