Allow users to create policies with shorter voting periods

[ryanchristo]

In the current implementation, a user sets the voting period when creating a group policy based on number of days. In some cases a user may want to set a shorter voting period. We should add support for days to be defined in decimals or the ability to change the unit (i.e. days to hours to seconds etc.).

As a side note, this would also improve the testing experience in a local development environment and when reviewing pull requests as I often find myself having to manually update daysToDuration to secondsToDuration.

[wgwz]

+1 for easier testing! i prefer the second option of being able to change the unit