Bug 1159067 - Read user cred from config

Bug 1159067 - [RFE] allow pulp to read user credentials from users admin.conf
if he/she does not want to provide password on command prompt
or --password in pulp-admin

this is basically for writing a batch job that would include multiple command lines together.
s/in user's local/in the user's/
Consider adding a period to end the sentence after ``~/.pulp/admin.conf``
Consider rewriting "for storing user credentials to avoid passing user credentials repeatedly on the command line." -> "Using the conf file avoids having to pass user credentials repeatedly using the command line. Also reading the password from a file that can only be read by certain users is more secure because it cannot be shown by listing the system processes."