* PT-2150 Fix tests for pt-mysql-summary
- Added POSIX environment to tests, so they do not depend on the local user environment
- Enabled keyring plugin on 8.0
- Fixed encryption information collection in 8.0, see also PT-1588
* PT-2150 Fix tests for pt-mysql-summary
- Added support of the environment variable DISABLE_KEYRING, so we can diable keyring plugin in sandbox/servers/start
* PT-2150 Fix tests for pt-mysql-summary
- Reverted changes in the expected output for tests 006 and 007 made by commit 9190b5e6ac
Because the tool now works properly again and can parse Percona XtraDB Cluster data
* PT-2150 Fix tests for pt-mysql-summary
- Added comment '--read-samples' back to the test cases
