Added docstring tests for some macros
Added docstring tests for some macros

Docstring tests for equilibrate, bind, bind_table, catalyze,
catalyze_state, catalyze_one_step, and catalyze_reversible.

alubbock/pysb-legacy,johnbachman/pysb,d-fan/pysb,d-fan/pysb,alubbock/pysb,johnbachman/pysb,spgarbet/pysb,pysb/pysb,LoLab-VU/pysb,LoLab-VU/pysb,spgarbet/pysb,alubbock/pysb-legacy,spgarbet/pysb,d-fan/pysb,alubbock/pysb-legacy,neurord/pysb,alubbock/pysb-legacy,neurord/pysb,jmuhlich/pysb,neurord/pysb