slugbuilder: Add gradle/grails buildpacks
slugbuilder: Add gradle/grails buildpacks

Closes #14

Signed-off-by: Jonathan Rudenberg <3692bfa45759a67d83aedf0045f6cb635a966abf@titanous.com>

jzila/flynn,Brandywine2161/flynn,philiplb/flynn,technosophos/flynn,mubassirhayat/flynn,supermario/flynn,whouses/flynn,ozum/flynn,shutej/flynn,rikur/flynn,Brandywine2161/flynn,flynn/flynn,felixrieseberg/flynn,GrimDerp/flynn,pkdevbox/flynn,supermario/flynn,tonicbupt/flynn,felixrieseberg/flynn,lmars/flynn,flynn/flynn,kgrz/flynn,arekkas/flynn,TribeMedia/flynn,Brandywine2161/flynn,lmars/flynn,shads196770/flynn,shads196770/flynn,philiplb/flynn,benbjohnson/flynn,josephglanville/flynn,ozum/flynn,josephglanville/flynn,whouses/flynn,ozum/flynn,tonicbupt/flynn,kgrz/flynn,justintung/flynn,schatt/flynn,kgrz/flynn,clifff/flynn,philiplb/flynn,schatt/flynn,whouses/flynn,felixrieseberg/flynn,Brandywine2161/flynn,tonicbupt/flynn,flynn/flynn,benbjohnson/flynn,lmars/flynn,shads196770/flynn,clifff/flynn,mubassirhayat/flynn,GrimDerp/flynn,supermario/flynn,felixrieseberg/flynn,GrimDerp/flynn,shads196770/flynn,GrimDerp/flynn,schatt/flynn,schatt/flynn,pkdevbox/flynn,josephglanville/flynn,benbjohnson/flynn,GrimDerp/flynn,philiplb/flynn,flynn/flynn,ozum/flynn,TribeMedia/flynn,pkdevbox/flynn,Brandywine2161/flynn,rikur/flynn,justintung/flynn,josephglanville/flynn,benbjohnson/flynn,mubassirhayat/flynn,mubassirhayat/flynn,jzila/flynn,benbjohnson/flynn,justintung/flynn,lmars/flynn,kgrz/flynn,whouses/flynn,technosophos/flynn,josephglanville/flynn,jzila/flynn,tonicbupt/flynn,technosophos/flynn,felixrieseberg/flynn,supermario/flynn,justintung/flynn,TribeMedia/flynn,GrimDerp/flynn,clifff/flynn,ozum/flynn,justintung/flynn,TribeMedia/flynn,josephglanville/flynn,pkdevbox/flynn,schatt/flynn,jzila/flynn,schatt/flynn,kgrz/flynn,tonicbupt/flynn,shads196770/flynn,pkdevbox/flynn,rikur/flynn,TribeMedia/flynn,arekkas/flynn,jzila/flynn,shads196770/flynn,TribeMedia/flynn,Brandywine2161/flynn,arekkas/flynn,justintung/flynn,ozum/flynn,technosophos/flynn,arekkas/flynn,rikur/flynn,whouses/flynn,philiplb/flynn,rikur/flynn,lmars/flynn,flynn/flynn,clifff/flynn,kgrz/flynn,pkdevbox/flynn,rikur/flynn,technosophos/flynn,jzila/flynn,clifff/flynn,supermario/flynn,clifff/flynn,supermario/flynn,benbjohnson/flynn,whouses/flynn,arekkas/flynn