Integration of PeopleTime module with Pandadocs

Use cases:

1. generate client invoice (monthly or project (aka phase) based) based on time and project taken from peopletime. Rate values could be taken from peopletime or from Pandadocs.

2. Generate payable (invoice) to/for employees (contractor) based on hours they have reported per period to peopletime and their internal rate. Could also be an option to generate an acceptance certificates