QoL updates

Merge pull request #4 from ScottPJones/spj/fixv06

Fix deprecation warning on Julia v0.6 and later

Initial Release

This package is for developing differential/difference/discrete stochastic models which are common in systems biological applications. Currently, the Reaction interface only allows you to define discrete Poisson-rate events. In the near future this will be expanded to allow users to have it build SDE/ODE equations as well.