Somerville et al. 2009 GMPE for Australia
first implementation of Allen 2012 GMPE
added test for Non-Cratonic Mean
added test for total std for Non-Cratonic
Allen 2012 GMPE + tests
Merge pull request #132 from monellid/a2012

Allen 2012 GMPE for Australia Hazard Model
Merge pull request #131 from monellid/s2009

Somerville et al. 2009 GMPE for Australia Hazard Model