This ticket adds the testing of the S3 extension to the Linux builders, namely the Ubuntu and Ubuntu ARM.

A new testing task will be written, which will take care of the following:

• Compiling the WiredTiger and the S3 extension on the platform
• Running the unit tests for the S3 extension's C++ class(es)
• Running the python tests for S3
• (In the future this task will run the tiered storage tests for the S3 extension)

This ticket is a precursor to getting WT-8720 done, which extends this testing to OS X and Windows.