move src to default package structure

src/main/java/gov/usgs/earthquake/nshmp/DeaggCalc.java

src/main/java/gov/usgs/earthquake/nshmp/DeaggEpsilon.java

src/main/java/gov/usgs/earthquake/nshmp/DeaggIml.java

src/main/java/gov/usgs/earthquake/nshmp/GroundMotions.java

src/main/java/gov/usgs/earthquake/nshmp/Hazard2018.java

src/main/java/gov/usgs/earthquake/nshmp/HazardCalc.java

src/main/java/gov/usgs/earthquake/nshmp/RateCalc.java

src/main/java/gov/usgs/earthquake/nshmp/ResponseSpectra.java

...ov/usgs/earthquake/nshmp/aws/HazardResultSliceLambda.java

...sgs/earthquake/nshmp/aws/HazardResultsMetadataLambda.java

.../usgs/earthquake/nshmp/aws/HazardResultsSlicerLambda.java

src/main/java/gov/usgs/earthquake/nshmp/aws/Util.java

src/main/java/gov/usgs/earthquake/nshmp/etc/GmmParams.java

src/main/java/gov/usgs/earthquake/nshmp/etc/HazMat.java

src/main/java/gov/usgs/earthquake/nshmp/etc/HazMatImpl.java

...in/java/gov/usgs/earthquake/nshmp/etc/HazMatSpectrum.java

...v/usgs/earthquake/nshmp/etc/ParentLastURLClassLoader.java

src/main/java/gov/usgs/earthquake/nshmp/package-info.java

...n/java/gov/usgs/earthquake/nshmp/site/CybershakeSite.java

...n/java/gov/usgs/earthquake/nshmp/site/NehrpSiteClass.java