provide a way to seed the generator to enable reproducible runs

[travi]

the randomness makes it really hard to track down an issue when it is not predictable when it will happen

• somehow print the seed in the test output (at least in a failure case)
• allow the ability to pass the seed to the generator so that the situation can be reproduced without waiting for it to randomly happen again
• lint rule to prevent committing a generator with a hardcoded seed

[travi]

chance does support passing a seed, but doesnt seem to have a way to get the seed that was used. this means, a seed would need to always be passed in order to print out the current one for every run, so i'd have to take over the randomness.

http://chancejs.com/#advanced