Michael Bynum

Our testing infrastructure should test examples.

See the implementation for the `save` methods in #43

Instead, the build harness should download things from MINLP-Lib once before tests are run. This is a better use of bandwidth.

We need to improve the imports within Coramin so that some dependencies can be optional. Examples include mpi4py and Metis.

We can probably do a better job with the `perform_dbt` methods of exploiting integer variables.

- pay special attention to constraint sense when replacing nonlinear/nonconvex terms with auxiliary variables.

When the `get_rhs_expr` methods were added to the relaxation objects, an inconsistency was introduced between `AlphaBBRelaxation` and the other relaxation classes. In order to get consistent behavior, `add_cut` will need...

Sine and cosine are only supported for a domain of -pi/2 to pi/2. This needs expanded. Additionally, support for tangent needs added.