Check inconsistent values

[pezholio]

Opening for discussion. Still needs a bit of work.

This PR checks the data types of each column and raises a warning if less than 90% aren't the same type.

Currently only scanning for numeric and alpha field types. Need to do something for date formats, and maybe codes and boolean?

[coveralls]

Coverage remained the same when pulling e65be07 on feature-check-consistency into 6002f1f on master.

[coveralls]

Coverage remained the same when pulling a3d8a79 on feature-check-consistency into 6002f1f on master.

[pezholio]

Added alphanumeric too. I'm going to do dates, but in a different PR after this one has been merged

[coveralls]

Coverage remained the same when pulling f76fd86 on feature-check-consistency into 6002f1f on master.