Gadma

Fix float problem with new versions of numpy.

Demes engine had an issue to multiply time twice by the generation time. It was fixed with small change.

- Fix bug with momentsLD engine for models with exponential or linear change
- Restrict momi2 to use only one core
- Use another scipy function for Nelder_mead algorithm (local)
- Make all histories with different parameters when structure is changed (e.g. from 1,1 to 2,1)
- Allow usage of models specified using gadma API

* Fix bug when failed model is reported as best (Issue 73 )
* Add additional checks for Bayesian optimization
* Add documentation about BO

- Add linear extrapolation for dadi (Issue 68 ).
- Engine momi is renamed in momi2.
- Add dominance rate in the params file interface.
- Fix bug with CLAIC evaluation (for any eps it was taken as 1e-2).
- We changed hyperparameters of GADMA2
- Fix minor bugs.
- Fix documentation