v0.12.0-beta

CHANGELOG
8cefac6 Fix typo in name of snap published mock file
038699c Add new collector plugins to PLUGIN_CATALOG
af4a940 Adding introduction to Plugin Authoring
381a96a Corrected typo in environment
981426b minor typos
81a4198 Frontloaded steps outlined by @candysmurf
9c2cff8 Formatting Best Practices doc
6a8301e Fix #674: Merge global config into plugin config for ProcessMetrics and PublishMetrics
e31128a Change log message from error to debug and log the correct namespace being added to cache
f1dc462 Adds sticky (plugin) routing strategy
e7605d4 Nominating Marcin for snap maintainer
9a5ab1c removes .vscode directory
f3923d9 added heka publisher plugin into committed section of plugin catalog
dc346ef Added Apache plugin to the list of committed plugins