added slack notifications for travis builds
added slack notifications for travis builds

lokinell/spock,lokinell/spock,alien11689/spock,raphw/spock,sebi-hgdata/spock,psideleau/spock,siordache/spock,sebi-hgdata/spock,raphw/spock,paplorinc/spock,siordache/spock,paplorinc/spock,leonard84/spock,raphw/spock,psideleau/spock,lokinell/spock,sebi-hgdata/spock,alien11689/spock,alien11689/spock,paplorinc/spock,psideleau/spock,siordache/spock,spockframework/spock