Remove invalid use statements

[shadowhand]

These use statements are importing the global Email, Exception, and Response classes. Since those classes do not exist, the local namespace'd classes are used instead.

This error becomes apparent when trying to use the Client class elsewhere.

[shadowhand]

Example of error message:

PHP Fatal error: Cannot use Email as Email because the name is already in use in /home/travis/build/RoundingWell/RWell/vendor/fastglass/sendgrid/src/Client.php on line 4

[taz77]

Thanks. I got to get busy to finish the conversion to v3. I just never find enough time to work on it because it's a huge rewrite.