Deprecate spy.reset() in favor of the more explicit spy.resetHistory()

[fearphage]

Spy currently has a reset method which functions as resetHistory. It would make the intention and functionality of the method more clear if it were named appropriately.

[fearphage]

The idea for this ticket started in #1424.

[GCHQDeveloper500]

Picked this one up as it was marked as "Help Wanted" - hope that's okay.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[mroderick]

This was done with #1630