message: Updated RELEASE-NOTES.
diff: @@ -12,10 +12,13 @@ The Axom project release numbers follow [Semantic Versioning](http://semver.org/
  ### Added
  ### Removed
  +- Replaced sidre::SidreLength with sidre::IndexType.
  +- Replaced usage of std::size_t in sidre with sidre::IndexType.
  ### Deprecated
  ### Changed
  +- Changed sidre::IndexType to be a 64bit signed integer.
  ### Fixed
  