Parent pom.xml: update to Solr 6.3.0.  reference solr-plugins module.
Parent pom.xml: update to Solr 6.3.0.  reference solr-plugins module.

dsmiley/hhypermap-bop,cga-harvard/hhypermap-bop,cga-harvard/hhypermap-bop,cga-harvard/hhypermap-bop,cga-harvard/hhypermap-bop,dsmiley/hhypermap-bop,cga-harvard/hhypermap-bop,cga-harvard/hhypermap-bop,cga-harvard/hhypermap-bop,dsmiley/hhypermap-bop