Release 0.51

This release introduces a new method run_scheduled_tasks and the general run_task command, that executes tasks, and aims to produce the output specified. For now basic plotting is implemented, but will be refined in the next versions.

It also includes a number of bugfixes (fixes #34, #35 , #36), thanks to @ayush9pandey for reporting. This should produce more applicable error messages when running simulations, sort an issue where Miriam information could not be retrieved when using python-copasi > 4.35 and clarify issues in the notebooks.

Full Changelog: v0.50...v0.51