Install link if in Pro and ArcMap installed
Install link if in Pro and ArcMap installed

If we are installing the bridge from ArcGIS Pro, check the registry
for ArcGIS 10.3.1, and if it exists, install the bridge in the
correct place as if we were installing in 10.3.1 directly.

giserh/r-bridge-install,R-ArcGIS/r-bridge-install,datasciencedev/r-bridge-install,R-ArcGIS/r-bridge-install,datasciencedev/r-bridge-install,giserh/r-bridge-install