Use plugin shapshot zips from Maven for BWC tests

[ankitkala]

Is your feature request related to a problem? Current implementation of BWC test requires CCR and security zips from the older version. We need to start using the plugin zips from Maven. Plugin zips are published to maven from 2.1 onwards. So, We can start using these for BWC from 3.0 (as we'd want to test again last major version)

What solution would you like? Fetch the CCR and Security ZIp for BWC tests from maven