Pymata-aio

Mask all data with 0x7f prior to transmission to firmata

Sonar required some additional changes to function properly.

This release addresses the problems of issue 35 and issue 36 .

This release resolves issue 32, fixes an issue with data latches and provides general code cleanup.

See the [changelog](https://github.com/MrYsLab/pymata-aio/blob/master/documentation/changelog.md) for details.

A new feature has been added. To use this feature you must use either FirmataPlus or FirmataPlusRB. The keep alive feature sends a periodic keepalive message to the arduino (the period length can be from 1 to 10 seconds and is configurable as a parameter in the new keep_alive method. The arduino expects to see the message within the period time frame, and if it does not, it resets itself.

Once keep_alive has been actuated, it can be turned off by specifying a period of zerio.