Refactored #member? to #cover?.
Refactored #member? to #cover?.
Optimized interpolation multiplications.
Merge pull request #1 from HotFusionMan/feature/optimize_member_to_cover

Feature/optimize member to cover
Optimized for speed and accuracy.
Merge branch 'feature/optimize_member_to_cover' into feature/optimize_interpolation
Merge branch 'feature/optimize_interpolation' of https://github.com/HotFusionMan/spliner into HotFusionMan-feature/optimize_interpolation
Compatibility with older rubies lup_decomposition
Added ruby 2.0.0 to Travis matrix
Merge remote-tracking branch 'upstream/master'