Packerlicious

BUG FIX:
* property 'attributes' not rendering in user templates due to internal usage [GH-172]

IMPROVEMENTS:
* builders: add support for named builds [GH-171]
* CHANGELOG: retroactive update [GH-170]

hashicorp/packer 1.3.5 feature sync [GH-168]

IMPROVEMENTS:
* builder/AmazonEbs: add attribute ena_support [GH-167]
* post-processor/Manifest: add attribute custom_data [GH-169]

* builder/TencentCloudCvm: add support for packer tencentcloud-cvm

IMPROVEMENTS:

* builder/GoogleCompute: add labels attribute [GH-166]

hashicorp/packer 1.3.4 feature sync