Remove find_dependencies from Telemetry

Telemetry's find_dependencies has reached the end of its deprecation cycle, and
the version in tools/perf is now the recommended one to use.

BUG=528331

Review URL: https://codereview.chromium.org/1472923003

Cr-Commit-Position: refs/heads/master@{#361185}

tools/telemetry/find_dependencies

-#!/usr/bin/env python
-# Copyright 2014 The Chromium Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-from telemetry import decorators
-from telemetry.internal.util import find_dependencies
-
-
-@decorators.Deprecated(2015, 11, 23, 'Please use tools/perf/find_dependencies.')
-def main():
-  find_dependencies.FindDependenciesCommand.main()
-
-
-if __name__ == '__main__':
-  main()