eager: add interp with deprecation

grudge/eager.py

@@ -45,6 +45,13 @@ def without_queue(ary):
 
 
 class EagerDGDiscretization(DGDiscretizationWithBoundaries):
+    def interp(self, src, tgt, vec):
+        from warnings import warn
+        warn("using 'interp' is deprecated, use 'project' instead.",
+                DeprecationWarning, stacklevel=1)
+
+        return self.project(src, tgt, vec)
+
     def project(self, src, tgt, vec):
         if is_obj_array(vec):
             return with_object_array_or_scalar(