Remove choco (coin-or#510)

* removing packaged choco

* updated history and version

added `timeMode` argument for counting cbc wall-time. (coin-or#487)

* added `timeMode` argument for counting cbc wall-time.

* bump pypi version and history

* increased the timeLimit and added seed to be sure to pass the test.

updated history

added mps to docs

pypi version bump and description.

make explicit inits for all solvers with standard interface. (coin-or…

…#326)

* make explicit inits for all solvers with standard interface.

* new changes to apis. Took out warmStart from the core object and into optionsDict.

* bump version

* fixes coin-or#280

updated contribution file and docs. (coin-or#316)

* updated contribution file and docs.

* added more docstrings to documentation.

Changes to satisfy pypi