add back string conversion functions. (#68)

move rescode back to main package. (#66)

use variable from header for enum values (#64)

Fix failing examples for mosek 10.1 (#59)

Update doc for slice input. (#57)

Update README (#55)

Move test to use `error` instead of `rescode`. (#54)

Return `error` for `gmsk.NewError`. (#51)

When converting a `nil` `gmsk.MskError` to `error`, it will actually
not be `nil`. This will fix that errenous behavior.

Clarify `NewError` method return nil for OK. (#50)

add `MskError` (#48)