MAINT: Remove unused future pricing stubs.

The FutureMinuteReader is now implemented by using a minute bar reader
with a different minutes per day value.

zipline/data/future_pricing.py

@@ -1,27 +0,0 @@
-# Copyright 2015 Quantopian, Inc.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-
-class FutureDailyReader(object):
-    """
-    Stubbed out. Currently unimplemented.
-    """
-    pass
-
-
-class FutureMinuteReader(object):
-
-    def __init__(self, rootdir, sid_path_func=None):
-        self.rootdir = rootdir
-        self.sid_path_func = sid_path_func