add 'public_key' property to Recurly.js
Merge remote-tracking branch 'upstream/master'
update CHANGELOG
Merge pull request #155 from mekhovov/master

Add 'public_key' property to Recurly.js
Add tax_code to plan, add on and adjustment

Used in tax calculations for VAT 2015 and
Avalara integration taxes.
Merge pull request #160 from recurly/jh-digital_services_vat_2015_api

Add tax_code to plan, add on and adjustment
Read and Write custom invoice notes from API