revert geo_interface move for PR coordination (#163)

Author: rafaqz

src/LibGEOS.jl

@@ -95,7 +95,7 @@ include("context.jl")
 include("wellknown.jl")
 include("geos_types.jl")
 include("geos_functions.jl")
-include("geointerface.jl")
+include("geo_interface.jl")
 include("strtree.jl")
 include("deprecated.jl")