Added one more test for mpenergies: check if Moller-Plesset corrections are negative for consecutive orders.
Added one more test for mpenergies: check if Moller-Plesset corrections are negative for consecutive orders.

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