Removed transitions and move to a Node based workflow element

apps/workflows/literals.py

@@ -7,3 +7,13 @@ OPERAND_CHOICES = (
     (OPERAND_OR, _(u'or')),
     (OPERAND_AND, _(u'and'))
 )
+
+NODE_TYPE_TASK = 'task'
+NODE_TYPE_START = 'start'
+NODE_TYPE_END = 'end'
+
+NODE_TYPE_CHOICES = (
+    (NODE_TYPE_TASK, _(u'Simple task')),
+    (NODE_TYPE_START, _(u'Start')),
+    (NODE_TYPE_END, _(u'End')),
+)