Update devel/py-lupa to version 1.3.

Changes since version 1.1:

1.3 (2016-04-12)

     * eval() and execute() accept optional positional arguments
     * calling str() on a Python object from Lua could fail if the
       LuaRuntime is set up without auto-encoding
     * attribute/keyword names were not properly encoded if the LuaRuntime
       is set up without auto-encoding
     * built with Cython 0.24

1.2 (2015-10-10)

     * callbacks returned from Lua coroutines were incorrectly mixing
       coroutine state with global Lua state (patch by Mikhail Korobov)
     * availability of python.builtins in Lua can be disabled via
       LuaRuntime option.
     * built with Cython 0.23.4


(alnsn)