Remove argparse from the requirements.txt.

The argparse module has been builtin to Python since
Python 3.2, released in 2011 (see
https://docs.python.org/3/whatsnew/3.2.html).  Further,
the argparse pip module has not been released or updated
since 2015, and lacks some of the features of the modern,
built-in argparse.  Drop the pip installed version in
favor of the built-in version.

Signed-off-by: Chris Lalancette <[email protected]>

Tools/setup/requirements.txt

@@ -1,5 +1,4 @@
 argcomplete
-argparse>=1.2
 cerberus
 coverage
 empy==3.3.4