remove optimize_model (it was not used)

clean up `change_objective`

document `optimize_objective`

closes #405

Fix error with screen and `unregister`

Completely remove all JuMP and COBREXA prefixes where possible

implement objective envelopes (aka production envelopes)

closes #267

display banner consistently at each import

Fixes #390

simplify code by removing unnecessary unicode

simplify trigger mechanism

slightly more useful issue/PR templates

closes #110

refs #110

unsupport `name` field in models

It looks great but we aren't going to support it in core MetabolicModel
interface. Moreover, it's only a prettification, which the users may manage
externally.

Closes #392 (name support will be implemented elsewhere)

compatibility with SBML 0.6

improve jsonmodel speed + some extra cleanup

Closes #350

Use Makie instead of Plots