feat(graph-builder) Accepts a source option.
feat(data.selection) Diff quotient now accepts an optional interval.
chore(example) Add example with actual network data.
chore(graph-builder) Add docs for options.sources
chore(data.selection) Diff quotient more generic interval.
fix(graph-builder) Stats should be calculated only from sources.
Merge pull request #128 from racker/non-negative-rate-of-change

Non negative rate of change.