Created modules for LPA dashboard
Add groupMappings to grouped_timeseries collection/module

Some grouped timeseries (eg LPA) use grouping that are not reflected in the data. Group these together in the collection.parse method.
Updated LPA dashbaord config
Added LPA availability stub
Removed reference to tax disc in LPA dashboard
Rename LPA table module slug to help-usage
Add info text to LPA modules
Merge pull request #285 from alphagov/feature/lpa-dashboard

LPA dashboard