update dependencies

Author: Pike

fluent.runtime/setup.py

@@ -20,7 +20,7 @@
       ],
       packages=['fluent', 'fluent.runtime'],
       install_requires=[
-          'fluent.syntax>=0.10,<=0.11',
+          'fluent.syntax>=0.12,<=0.13',
           'attrs',
           'babel',
           'pytz',

fluent.runtime/tox.ini

@@ -6,10 +6,8 @@ skipsdist=True
 setenv =
     PYTHONPATH = {toxinidir}
 deps =
-     fluent.syntax>=0.10,<=0.11
+     fluent.syntax>=0.12,<=0.13
      six
      attrs
      Babel
-     py27: singledispatch
-     pypy: singledispatch
 commands = ./runtests.py