Initial commit of Boore et al 1997 GMPE
Merge branch 'master' into bjf1997_gmpe
Merges upstream changes, adds docs, pep8 fixes
Boore et al (1997) GMPE now passes tests
Fixes error in doc. Corrects docstrings in some functions
Changes class names, fixes divide by 0 on tests
Minor fixes to address review comments
Merge pull request #148 from g-weatherill/bjf1997_gmpe

Implements the Boore, Joyner & Fumal (1997) GMPE