Using these instructions (http://trac.osgeo.org/postgis/wiki/UsersWikiPostGIS23UbuntuPGSQL96Apt), I tried to install Postgis on the postgres database. When I get down to "Create Extension Postgis", postgres is telling me that it cannot find the "postgis.control" file. I searched the directory and it wasn't located anywhere on the server. I even looked for "postgis.sql" and "spatial_ref_sys.sql" on the server and couldn't find those.
Is there a problem with the package "postgresql-9.6-postgis-2.3" because it seems to be missing the "postgis.control" and other postgis files?
