The main purpose is to update the code to Rust 1.37.

The following are the commits that will be picked:

71faddb - Update to Rust 1.37
dec1663 - Remove done task
420b2c7 - Update README
4c46209 - Add more info to the device source tests
8d5ee7f - Move tests for device APIs from tests/api.rs to tests/device_property.rs
9f48fee - Update todo
29aabff - Re-organize the tests for the aggregate device
8336ace - Revise the comments about tests for aggregate device
ed29d9b - Remove unused functions
534bd2d - Add missing AggregateDevice::destroy_device in the tests
25149a0 - Revise the tests for AggregateDevice::destroy_device
bdf5649 - Revise the tests for AggregateDevice::activate_clock_drift_compensation
b03b23a - Revise the tests for AggregateDevice::set_master_device
630bd25 - Revice the tests for AggregateDevice::set_sub_devices
684950e - Revise the tests for AggregateDevice::get_sub_devices
84557c3 - Move lines of the test for AggregateDevice::create_blank_device_sync
ac06962 - Clean the test for AggregateDevice::create_blank_device_sync
b132620 - Simplify the APIs to get the device info from hardware (#6)
47d77c1 - Remove the duplicate tests
4b948c1 - Revice comments for tests in device_change.rs
fba64b2 - Add tests that simulate uplugging devices on active streams
09d4668 - Set default callbacks in the tests for checking device_changed_callback
50458dd - Remove unnecessary parentheses
4ca0a1c - Rename the tests for AggregateDevice::get_sub_devices

Pushed by rmaries@mozilla.com:
https://hg.mozilla.org/integration/autoland/rev/e43a9b12b35b
Update cubeb-coreaudio-rs to version 71faddb. r=kinetik

https://hg.mozilla.org/mozilla-central/rev/e43a9b12b35b