aux_variables are not removed anymore if a reaction becomes irreversible
Fixing a few issues with _cycle_free_fva
More fixes and tests
Removed print statement
More detailed timestamp for _check_freshness
metabolite._reaction should be just a set, not frozenset
gene._reaction should also be a set and not a frozenset
Push all changes for Emre
Retrieve reverse_variable after one has been potentially added
Merge pull request #5 from biosustain/Fix_nikos_problems

Retrieve reverse_variable after one has been potentially added
Fix previous fix with reverse_variable
Fixes add_demand not changing affected constraint
Remove more print statements
Removed cycle free fva test
Fixed effective_lower/upper_bound
get_primal_by_id uses x_dict now
Removed FIXME statements for effective_lower_bound
Call cobrapy add_reactions before cameo specific code
Fixed reference heuristic results (reaction_knockout_single_objective.pkl was even empty!) necessary due to now correctly working get_primal_by_id
Updated optlang SHA (541273d0fcbe59f8922943ce9b8c2ad7d94c18dc)