Bump org.codehaus.groovy:groovy-all from 2.3.9 to 2.4.21 in /clover-groovy/src/test/resources/spock-example

Bump org.codehaus.groovy:groovy-all from 2.3.9 to 2.4.21 in /clover-groovy/src/test/resources/spock-example #224