NIFI-4870 Upgraded activemq-client and activemq-broker versions to 5.…

[alopresto]

…15.3.

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[mosermw]

Hi @alopresto, should we update the copyright year to 2018 in the applicable NOTICE files?

[alopresto]

Updated copyright years to 2017 (as referenced in activemq NOTICE).

[mcgilman]

Will review...

[mcgilman]

Thanks @alopresto! This has been merged to master.