Gate times are not exposed in the device specs API

The device.specs object provides the T1/T2 times for each gate:

>>> import pyquil
>>> device = pyquil.api.get_devices(as_dict=True)['8Q-Agave']
>>> device.specs.T1s()
{0: 1.07e-05, 1: 1e-05, 2: 1.55e-05, 3: 1.42e-05, 4: 1.46e-05, 5: 1.49e-05, 6: 1.42e-05, 7: 1.32e-05}
>>> device.specs.T2s()
{0: 1.06e-05, 1: 9.2e-06, 2: 1.25e-05, 3: 1.85e-05, 4: 2.62e-05, 5: 1.28e-05, 6: 1.29e-05, 7: 1.77e-05}

however, the actual gate times are not exposed in the API.

As such, there is no way of accurately using that information to compute the circuit depths (other than using the estimated ballpark values of 50 ns for 1-qubit gates and 150 ns 2-qubit gates).

Start at the device.specs API returned by pyquil.api.get_devices(as_dict=True), alongside the existing T1s() and T2s() entry points. Trace how device specifications are represented and identify where gate timing data should be exposed. Done means callers can retrieve the actual one- and two-qubit gate times through the device specs API.