Set pylint version to ensure compatibility with python 2.6
Set pylint version to ensure compatibility with python 2.6

JohnLZeller/jenkinsapi,aerickson/jenkinsapi,jduan/jenkinsapi,salimfadhley/jenkinsapi,zaro0508/jenkinsapi,aerickson/jenkinsapi,mistermocha/jenkinsapi,JohnLZeller/jenkinsapi,imsardine/jenkinsapi,mistermocha/jenkinsapi,domenkozar/jenkinsapi,JohnLZeller/jenkinsapi,imsardine/jenkinsapi,imsardine/jenkinsapi,salimfadhley/jenkinsapi,zaro0508/jenkinsapi,mistermocha/jenkinsapi,jduan/jenkinsapi,domenkozar/jenkinsapi,zaro0508/jenkinsapi