1.6.0-alpha.0

Supermarket Omnibus package fixes:

• [#8] Fix issue where cookbooks cannot be uploaded
• [#10] Fix issue where cookbooks cannot be downloaded by Berkshelf

Upstream Supermarket fixes:

• [chef/supermarket#934] Only show source/issues URLs if they're present
• [chef/supermarket#936] Add powershell modules and dsc resources to available tool types
• [chef/supermarket#937] List which FEATURES are enabled in the health endpoint
• [chef/supermarket#942] Add a button for sorting search results by release date
• [chef/supermarket#945] Show contributors even if GH is disabled
• [chef/supermarket#946] Show code of conduct in the footer
• [chef/supermarket#951] Adding changelogs to more Atom feeds
• [chef/supermarket#952] Add docs on feature flags to the README
• [chef/supermarket#953] Fix error with empty collections in atom feeds
• [chef/supermarket#959] Return an error message when processing a corrupted tarball
• [chef/supermarket#968] Added AIX platform logo
• [chef/supermarket#971] Fix incorrect training URL