Documentation bug for YAML format

[leesharma]

One of the documentation examples in Solution (link to code | link to site) demonstrating that Species and Reactions can be imported from input files to construct Solutions appears to be invalid in 2.5. When using yaml inputs, ct.Reaction.listFromFile needs a Kinetics object as the second argument.

Solution objects can also be constructed using Species and Reaction objects which can themselves either be imported from input files or defined directly in Python:

spec = ct.Species.listFromFile('gri30.yaml')
rxns = ct.Reaction.listFromFile('gri30.yaml')  ## broken ##
gas = ct.Solution(thermo='IdealGas', kinetics='GasKinetics',
                  species=spec, reactions=rxns, name='my_custom_name')

The example should probably be corrected (either adding the second argument or switching back to cti/xml) or removed. The issue was introduced in #696, which updated a bunch of *.cti to *.yaml in the docstrings.