Add Distributions report class

New Distributions report class with updated README
Refactor aggregate helpers and add Dist report

New aggregate report Inbound ACD Call Attempts report with updated README. In
addition, multiple keys in response data were short-circuiting helpers that
build readable hashes of output. New helpers require
ActiveSupport::OrderedHashes to maintain valid associations with response keys,
and ensure that no columns are table rows are left unlabelled. Added this
dependency to gem and made all classes of aggregate reports build the
appropriate style of hash for ::key_translations.
Refactor Agent-level reports and helpers

All reports now use an ActiveSupport::OrderedHash to represent
::key_translations. Refactor
CompositeAgentLevelReportHelpers.parsed_response to execute on O(n).
Add Acd Attempts, by Queue report

New aggregate report AcdAttemptsByQueue with updated README
Add Acd Attempts, by Terminal analysis

New composite aggregate report AcdAttemptsByTerminal with updated README
Increment version for new release