som-10.1.8: ChangeLog.md

# Changelog for som

10.1.8 Revamped to work with Nix + cabal-install.

10.1.7 Revamped to work with Nix + Stack.

10.1.6 Removed SGM2 and SGM3; they aren't ready for use.

10.1.5 Bug fix in SGM3.

10.1.4 Modified SGM3 to work with limited range floating point types.

10.1.3 Added SGM3.

10.1.2 Fixed a warning.
       Added SGM2.

10.1.1 Fixed a warning.
       Added more documentation.

10.0.1 Upgraded to Stackage lts-12.16.

10.0.0 Revamped to work with Stack v1.7.1.

## Unreleased changes