Removed imports.
Use random initial surface; Added simple doctests.
Make bmi into a package.
Import BmiPoisson with package.
Initialize with defaults if no filename.
Update to use new bmi model.
Remove unused testing script.
Fix attibute names for Poisson class.
Update testing scripts with new BmiPoisson.
Clean up unused code.
Create nose tests.
Nose tests for get_value.
Get time from embedded Poisson object.
Implemented get_time_step method.
Fixed self._update to self.update.
Fixed update_frac.
Added nose tests for irf methods.
Nose tests for grid info and set_value methods.
Removed testing folder in favor of nose tests.