postgis 2.1.3

[kashif]

added recommended dependency on sfcgal see #29680

[dakcarto]

Failed build bot report has no failed tests. ?

The addition of sfcgal is optional in the documented build requirements for 2.1. However, so is gdal and that's :recommended as well. Since the docs indicate the use of postgis.backend variable to switch to optionally use SFCGAL to override some GEOS functions, there should be no harm in having depends_on "sfcgal" => :recommended, especially since it adds extra 3D data support.

The only issue I see is for those users compiling. The extra cgal dependency adds compiling of boost; but, most users will be using bottles, so not a big issue.

@kashif I think you will want to use double quotes for newly added code to the formula, as per style guide.

[kashif]

thanks I will do that in the future!

[jacknagel]

@BrewTestBot test this please