argparse is already included in python3.6

Index: tarsnapper.egg-info/requires.txt
--- tarsnapper.egg-info/requires.txt.orig
+++ tarsnapper.egg-info/requires.txt
@@ -1,4 +1,3 @@
-argparse>=1.1
 pyyaml>=3.09
 python-dateutil>=2.4.0
-pexpect>=3.1
\ No newline at end of file
+pexpect>=3.1
