Merge pull request #523 from alimony/patch-1

Fix typo.
diff --git a/jinja2/filters.py b/jinja2/filters.py
index e5c7a1a..cd89f6f 100644
--- a/jinja2/filters.py
+++ b/jinja2/filters.py
@@ -44,7 +44,7 @@
 
 
 def environmentfilter(f):
-    """Decorator for marking evironment dependent filters.  The current
+    """Decorator for marking environment dependent filters.  The current
     :class:`Environment` is passed to the filter as first argument.
     """
     f.environmentfilter = True