Make LIVE Tests configurable with ENV

To enable ldap live test, set the environmental variable
``ENABLE_LDAP_LIVE_TESTS`` to a non-false value.

To enable tls ldap live test, set the environmental variable
``ENABLE_TLS_LDAP_LIVE_TESTS`` to a non-false value.

To enable mysql sql live test, set the environmental variable
``ENABLE_LIVE_MYSQL_TESTS`` to a non-false value.

To enable postgres sql live test, set the environmental variable
``ENABLE_LIVE_POSTGRES_TESTS`` to a non-false value.

To enable db2 sql live test, set the environmental variable
``ENABLE_LIVE_DB2_TESTS`` to a non-false value.

This allows for running all tests in a standard run by simply setting
the appropriate environmental variables.

This moves the live tests to be skips if the specific live-test
environmental variables are not set.

Change-Id: I8c09a8dcfca3f9691306c5f416f688205171bda3
Closes-Bug: 1243392
Merge "Make LIVE Tests configurable with ENV"