Consider renaming SauceLabsCoreTest.php.bak file

Problem/Motivation

There is a file at top level called:

SauceLabsCoreTest.php.bak

People tend to use .bak for making backups of a file before they edit them so it makes it look like this is a mistake and should not be in the codebase.

Proposed resolution

Consider renaming this to make it more clear.

Remaining tasks

Think about a better name and propose ideas.

User interface changes

n/a

API changes

n/a

Data model changes

n/a