updated test path names

...t/java/gov/usgs/earthquake/nshmp/gmm/UsgsPrviCrustal.java

...java/gov/usgs/earthquake/nshmp/gmm/UsgsPrviInterface.java

...test/java/gov/usgs/earthquake/nshmp/gmm/UsgsPrviSlab.java

src/test/resources/gmm/prvi-active-crust-results.csv

src/test/resources/gmm/prvi-interface-results.csv

src/test/resources/gmm/prvi-intraslab-results.csv