change version to 0.2.0-dev
pep8 cleanup
add test that ensures that there is at least one edges-only subgraph
modify test to check that there is exactly one all-edges sg
move all checks and test into one encompassing function
This improves code reuse
add edges-only check to encompassing function
add subgraph multiplicity check
For each subgraph we ensure that the number of species and reactions
is exactly equal to the number of species and reactions of the
corresponding fragment
add constants for current data structures
pep8 cleanup
add functions that return species and reactions of a subgraph
Add test that ensures that subgraphs match subgraph motifs
Subgraph motifs are computed from subgraph components, and their key must correspond
uniquely to exactly one subgraph in the corresponding fragment
add check for Ks constant computed