Update CHANGES
Update CHANGES

Whitelist `exists` arel method from SQL injection check
Fix attribution of cyclic ancestors fix

jeffyip/brakeman,cheerfulstoic/brakeman,jlecour/brakeman,dfens/brakeman,spcoder/brakeman,liqites/brakeman,spcoder/brakeman,github/brakeman,github/brakeman,dfens/brakeman,liqites/brakeman,jeffyip/brakeman,spcoder/brakeman,jlecour/brakeman,jakeatwork/brakeman,htdc/brakeman,cheerfulstoic/brakeman,htdc/brakeman,masarakki/brakeman,bf4/brakeman,kbrock/brakeman,jakeatwork/brakeman,liqites/brakeman,dfens/brakeman,kbrock/brakeman,jakeatwork/brakeman,bf4/brakeman,lee-leon/brakeman,lee-leon/brakeman,bf4/brakeman,masarakki/brakeman,kbrock/brakeman,cheerfulstoic/brakeman,htdc/brakeman,masarakki/brakeman,lee-leon/brakeman,jlecour/brakeman