commerce_pos 7.x-2.0-beta6

2 big features and a number of smaller bugfixes for this release. The features are:

• Anonymous user creation: Add email or phone number for quick creation of accounts during checkout and payment terminal support.
• Payment Terminal Support: Finally push and pull charges to your physical payment terminals, needs a payment terminal plugin as well, but we've got our first one available in sandbox for Paymentree (supports many terminal types) https://www.drupal.org/sandbox/tbradbury/2745927

#2772989: Tax calculations not working by Scott Robertson: Tax calculations not working
#2770271: Fatal error from bad hook implementation by Scott Robertson: Fatal error from bad hook implementation
#2762529: Email Receipt Rule Missing by Scott Robertson, kfitz: Email Receipt Rule Missing
#2752355: Anonymous User Creation and Phone Number Capture by kfitz, Scott Robertson, smccabe: Anonymous User Creation and Phone Number Capture
#2765549: Reporting module typo by kfitz: Reporting module typo
#2767177: Voided payments show up normally in receipts by Scott Robertson: Voided payments show up normally in receipts
#2767175: Order discounts have a "Remove" link in receipts by Scott Robertson: Order discounts have a "Remove" link in receipts
#2766309: "To Pay" amount is almost invisible by Scott Robertson, snetzlaw: "To Pay" amount is almost invisible
#2746605: Add support for payment terminal plugins by Scott Robertson, tbradbury: Add support for payment terminal plugins
#2761103: Use Gulp for compiling Sass by Scott Robertson: Use Gulp for compiling Sass
#2762313: Update error by tbradbury, s1biose: Update error