Auto merge of #2394 - micbou:move-client-tests, r=Valloric

[READY] Move client tests to the main tests folder

This makes it possible to configure all tests at a package level by implementing the `setUpPackage` and `tearDownPackage` functions in `python/ycm/tests/__init__.py` file.

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python/ycm/tests/client/completion_request_test.py

@@ -27,7 +27,7 @@ from nose.tools import eq_
 from ycm.tests.test_utils import MockVimModule
 vim_mock = MockVimModule()
 
-from .. import completion_request
+from ycm.client import completion_request
 
 
 class ConvertCompletionResponseToVimDatas_test( object ):