Fix to collect region from aws_config_file for specified profile

[dheerajd-msys]

Signed-off-by: dheerajd-msys dheeraj.dubey@msystechnologies.com

Description

• Per issue region was being set default i.e. us-east-1 from aws_config_file for specified profile
• Handles collecting mentioned region from aws_config_file for particular profile

Issues Resolved

Fixes #614

Output Post Fix

PS E:\Backup\Project\Chef_Repo\knife-ec2> bundle exec knife ec2 server list --aws-profile dheeraj -VV 
DEBUG: Using AWS config file at C:/Users/chef/.aws/config
DEBUG: Using AWS credential file at C:/Users/chef/.aws/credentials
DEBUG: Using AWS profile dheeraj
DEBUG: Using AWS region us-west-2
DEBUG: Setting up AWS connection using aws_access_key_id xxxxxx aws_secret_access_key: xxxxxx aws_session_token:
Instance ID          Name  Public IP  Private IP    Flavor    Image                  SSH Key  Security Groups   State
i-03fbe44fe9b2fab80                   172.31.16.77  t2.micro  ami-0c5204531f799e0c6           launch-wizard-31  stopped
PS E:\Backup\Project\Chef_Repo\knife-ec2>

Check List

• New functionality includes tests
• All tests pass
• All commits have been signed-off for the Developer Certificate of Origin. See https://github.com/chef/chef/blob/master/CONTRIBUTING.md#developer-certification-of-origin-dco
• PR title is a worthy inclusion in the CHANGELOG