[Telemetry] Add pyfakefs to telemetry/third_party

tools/telemetry/third_party/pyfakefs/pyfakefs/README.md

+# pyfakefs
+pyfakefs implements a fake file system that mocks the Python file system modules.
+Using pyfakefs, your tests operate on a fake file system in memory without
+touching the real disk.  The software under test requires no modification to
+work with pyfakefs.
+
+## Usage
+See the [usage tutorial](http://github.com/jmcgeheeiv/pyfakefs/wiki/Tutorial)
+for a concrete example of how to apply pyfakefs.
+
+## Continuous Integration
+pyfakefs is tested with Python 2.6 and above.  See [Travis-CI](http://travis-ci.org) for
+[pyfakefs continuous integration test results](https://travis-ci.org/jmcgeheeiv/pyfakefs)
+for each Python version.
+
+## Installation
+
+### Compatibility
+pyfakefs works with Python 2.6 and above.  pyfakefs has no dependencies beyond the Python
+standard library.
+
+### PyPi
+pyfakefs project is hosted on PyPi and can be installed:
+
+```bash
+pip install pyfakefs
+```
+
+## History
+pyfakefs.py was initially developed at Google by Mike Bland as a modest fake
+implementation of core Python modules.  It was introduced to all of Google
+in September 2006. Since then, it has been enhanced to extend its
+functionality and usefulness.  At Google alone, pyfakefs is used in over 2,000
+Python tests.
+
+pyfakefs was released to the public in 2011 as Google Code project
+[pyfakefs](http://code.google.com/p/pyfakefs/).
+
+Fork
+[jmcgeheeiv-pyfakefs](http://code.google.com/p/jmcgeheeiv-pyfakefs/)
+added a [usage tutorial](http://github.com/jmcgeheeiv/pyfakefs/wiki/Tutorial),
+direct support for [unittest](http://docs.python.org/2/library/unittest.html)
+and [doctest](http://docs.python.org/2/library/doctest.html).
+
+Fork
+[shiffdane-jmcgeheeiv-pyfakefs](http://code.google.com/p/shiffdane-jmcgeheeiv-pyfakefs/)
+added further corrections.
+
+After the [shutdown of Google Code was announced,](http://google-opensource.blogspot.com/2015/03/farewell-to-google-code.html)
+all three Google Code projects are merged together here on GitHub as pyfakefs.
+