Added unit test for grad attribute in testGeoOpt for Gaussian parser.
Added unit test for grad attribute in testGeoOpt for Gaussian parser.

Schamnad/cclib,Clyde-fare/cclib,ben-albrecht/cclib,langner/cclib,ben-albrecht/cclib,Clyde-fare/cclib,andersx/cclib,jchodera/cclib,Schamnad/cclib,ghutchis/cclib,ATenderholt/cclib,jchodera/cclib,gaursagar/cclib,langner/cclib,cclib/cclib,berquist/cclib,berquist/cclib,gaursagar/cclib,andersx/cclib,langner/cclib,cclib/cclib,berquist/cclib,ghutchis/cclib,ATenderholt/cclib,cclib/cclib