updated test tables with values produced by GSC official code
updated test tables with data produced by original GSC code
Merge branch 'master' into ab1995-Mlg2Mw
magnitude conversion equation in Atkinson and Boore 1995 GMPE
updated test docs
Merge pull request #189 from monellid/ab1995-Mlg2Mw

Magnitude conversion equation in Atkinson & Boore 1995 GMPE