change context_class to dict when django_version is greater than 1.8

- this resolves deprecation warnings for projectes that use django1.8

Author: sudomakeinstall2

django_forms_bootstrap/templatetags/bootstrap_tags.py

@@ -3,7 +3,7 @@
 from django import VERSION as DJANGO_VERSION
 
 
-if DJANGO_VERSION >= (1, 10, 0):
+if DJANGO_VERSION >= (1, 8, 0):
     context_class = dict
 else:
     # Django<1.10 compatibility