Increment python debugger version in preparation for releasing 3.7.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=208671429

Increment Python agent version.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=192156908

Increment python agent version.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=191486696

Increment Python debugger version.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=190137963

Add notes to GitHub README about Python 3 support.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=189375958

Increment python agent minor version to 2.4

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=185848633

Release python agent version 2.3

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=179227554

Increment python agent minor version to 2.2

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=167292554

Removes meta_path based import hook mechanism. The meta_path mechanis…

…m causes breakpoints to be activated before the module is fully loaded. Instead, uses a combination of (module,name,fromlist) to identify all modules were touched by the import.

Note: Let's also test this manually before submitting.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=166487604

Increment python agent version to 2.0

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=166082121