postgresql 12.1

Also fix pg_config paths.

Formula/postgresql.rb

@@ -1,9 +1,8 @@
 class Postgresql < Formula
   desc "Object-relational database system"
   homepage "https://www.postgresql.org/"
-  url "https://ftp.postgresql.org/pub/source/v11.5/postgresql-11.5.tar.bz2"
-  sha256 "7fdf23060bfc715144cbf2696cf05b0fa284ad3eb21f0c378591c6bca99ad180"
-  revision 1
+  url "https://ftp.postgresql.org/pub/source/v12.1/postgresql-12.1.tar.bz2"
+  sha256 "a09bf3abbaf6763980d0f8acbb943b7629a8b20073de18d867aecdb7988483ed"
   head "https://github.com/postgres/postgres.git"
 
   bottle do
@@ -30,6 +29,7 @@ class Postgresql < Formula
       --prefix=#{prefix}
       --datadir=#{HOMEBREW_PREFIX}/share/postgresql
       --libdir=#{HOMEBREW_PREFIX}/lib
+      --includedir=#{HOMEBREW_PREFIX}/include
       --sysconfdir=#{etc}
       --docdir=#{doc}
       --enable-thread-safety
@@ -56,7 +56,11 @@ class Postgresql < Formula
     system "make"
     system "make", "install-world", "datadir=#{pkgshare}",
                                     "libdir=#{lib}",
-                                    "pkglibdir=#{lib}/postgresql"
+                                    "pkglibdir=#{lib}/postgresql",
+                                    "includedir=#{include}",
+                                    "pkgincludedir=#{include}/postgresql",
+                                    "includedir_server=#{include}/postgresql/server",
+                                    "includedir_internal=#{include}/postgresql/internal"
   end
 
   def post_install