Initial Push Frame sensor model (#374)

CMakeLists.txt

bin/usgscsm_cam_test.cc

include/usgscsm/UsgsAstroPushFrameSensorModel.h

jupyter_notebooks/OrbitalPushFrameGeneration.ipynb

src/UsgsAstroPlugin.cpp

src/UsgsAstroPushFrameSensorModel.cpp

tests/CMakeLists.txt

tests/Fixtures.h

tests/PluginTests.cpp

tests/PushFrameCameraTests.cpp

tests/data/orbitalPushFrame.json