Feature/exampledata: Code for generation of example program with objects and mappings

Allows random generation of program and associated objects.

- Generate by logging in as admin and sending GET request to path `/admin/seedrandom`  (on localhost you can just call the script itself, `src/ggrc/seed/random_prog.py`).

- That prefixes every object and the program with "EXAMPLE".  To choose an arbitrary prefix, call `/admin/seedrandom/withprefix/<prefix>` instead.

- Currently set to generate 9 of each type of governance object, 15 of each type of business objects and each object mapped to 5 others (except 7 when governance to business).

- No constraint on what objects can be matched to what other objects except that an object cannot map to its own type.