Lowercasing keys breaks @odata.bind

[Majora320]

In all of the create/update functions in _odata.py, _lowercase_keys is called, but this breaks @odata.bind parameters as the keys are case sensitive to the table name. This is probably Microsoft's implementation of odata doing things wrong here, but there needs to be a way to create/update records with lookup columns.

[JoshuaDBruton]

Hey @Majora320 I have this issue as well.

So just bumping.
Seems like a major oversight, like nobody tested related columns in a DB service?