This update for python-boto fixes the following issues:

- Update in SLE-15: (bsc#1171769)
- Fix build under python3.8 by skipping more tests that break with previous release.
- Skip the tests for the flavors not being built
- Remove old comment
- Fix breakages caused by removing boto.cacerts module which is imported elsewhere in
  the package. The file boto/cacerts/cacerts.txt is removed instead, and
  boto-no-builtin-certs.patch is trimmed.
- Activate the test suite, adding many build dependencies with versions. 11 failing Cloudfront
  signings tests are skipped only on Python 3.
- Add versions to runtime dependencies.
- python-rsa is added as a Recommends as it is needed for Cloudfront.
- python-requests is added as a Recommends as it is needed for Cloudsearch.
- python-requests is added as a Suggests as it is used for contrib ymlmessage.