unpin the boto from setup.cfg

[omkarkhatavkar]

>>> from wrapanapi import EC2System
>>> client = wrapanapi.EC2System(username='username', password='password', region='us-west-2')
>>> client.create_vm('ami-0686851c4e7b1a8e1')
<wrapanapi.systems.ec2.EC2Instance system=<EC2System> raw=<boto3.resources.factory.ec2.Instance>, kwargs['uuid']='i-uuid'>

>>> client.list_vms()
[<wrapanapi.systems.ec2.EC2Instance system=<EC2System> raw=<boto3.resources.factory.ec2.Instance>, kwargs['uuid']='i-uuid'>]

[mshriver]

I think this is a change we need to make for wrapanapi to stay recent with AWS.

There is some risk involved here if we hit breaking changes, but looking through the changelog from 1.10.50 to 1.21.5 the maintainers of boto3 have not made any breaking changes in all of that time. Only updating AWS clients and bug fixes.