v.0.0.4 Logic to skip empty sheets (#4)

v.0.0.4 Logic to skip empty sheets (#4)

* v.0.0.2 schema and sync changes

Change number json schema to anyOf with multipleOf; skip empty rows; move write_bookmark to end of sync.py

* v.0.0.3 Sync activate version and error handling

Update README.md documentation. Improved logging and handling of errors and warnings. Better null handling in Discovery and Sync. Fix issues with activate version messages.

* v.0.0.4 Skip empty worksheets

Add logic to skip empty worksheets in Discovery and Sync mode.

* schema.py fix number datatype issue

Nomber datatypes are being created as strings in targets. The JSON schema order needs to be adjusted so that order is null, number, string.