(maint) update clj-parent to 5.2.6
(maint) update clj-parent to 5.2.6

This updates clj-parent to 5.2.6 which contains references to the
newer versions of bouncy-castle. In a recent change bouncycastle
renamed their library to 18on from 15on. The references in this project
were also updated.

puppetlabs/jvm-ssl-utils,puppetlabs/jvm-ssl-utils