CRAN Release 0.3.0

This is a major release for merTools with improvements to nearly all core functions, documentation, and helper functions. Most importantly, results from predictInterval for this version will be significantly more accurate than for previous versions, owning to a change in the way the intervals are calculated using the residual model error.

See the news.md file for a full list of changes. This is the last preview release before a planned 1.0 release later in 2017.