Add support for MOI.RelativeGapTolerance and MOI.AbsoluteGapTolerance

[odow]

Closes #209

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 48.12%. Comparing base (c55d106) to head (33a33b8).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #224 +/- ## ========================================== - Coverage 50.13% 48.12% -2.01% ========================================== Files 9 9 Lines 4807 4596 -211 ========================================== - Hits 2410 2212 -198 + Misses 2397 2384 -13 ```

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.