[raspbian] Remove render method from Raspbian backend

Author: Ritwick DSouza

netjsonconfig/backends/raspbian/raspbian.py

@@ -17,22 +17,11 @@ class Raspbian(BaseBackend):
         converters.DnsSearch,
         converters.Ntp
     ]
-    renderer = [
+    renderers = [
         Hostname,
         Hostapd,
         Interfaces,
         Resolv,
         Ntp,
         Commands
     ]
-
-    def render(self, files=True):
-        self.validate()
-        if self.intermediate_data is None:
-            self.to_intermediate()
-        output = ''
-        for renderer_class in self.renderer:
-            renderer = renderer_class(self)
-            output += renderer.render()
-            del renderer
-        return output