can't get a token when specifying a role on CLI

[gdestuynder]

1. call maws with a -r parameter while your STS token is expired: maws -r arn:aws:iam::320464205386:role/MAWS-Admin -o awscli

2. Get an error / no web window open / maws is stuck until ^C

Error:

1 kang@xps13 ~ % maws -r arn:aws:iam::320464205386:role/MAWS-Admin -o awscli                                                    :(
ERROR:mozilla_aws_cli.sts_conn:AWS STS Call failed 400 : <ErrorResponse xmlns="https://sts.amazonaws.com/doc/2011-06-15/">
  <Error>
    <Type>Sender</Type>
    <Code>ExpiredTokenException</Code>
    <Message>Token too old: 153938</Message>
  </Error>
  <RequestId>cdebddb1-1779-11ea-9b4b-f55ed4088ab3</RequestId>
</ErrorResponse>

ERROR:mozilla_aws_cli.sts_conn:AWS STS Call failed 400 : <ErrorResponse xmlns="https://sts.amazonaws.com/doc/2011-06-15/">
  <Error>
    <Type>Sender</Type>
    <Code>ExpiredTokenException</Code>
    <Message>Token too old: 153939</Message>
  </Error>
  <RequestId>ce9abb7f-1779-11ea-9a9e-7fd145c5b7e6</RequestId>
</ErrorResponse>

ERROR:mozilla_aws_cli.login:AWS STS Call failed when attempting to assume role arn:aws:iam::320464205386:role/MAWS-Admin with amr ['', 'mozilliansorg_mozilla-iam-aws-access', 'team_opsec'] iss https://auth.mozilla.auth0.com/ and aud N7lULzWtfVUDGymwDs0yDEq6ZcwmFazj
ERROR:mozilla_aws_cli.login:Unable to assume role arn:aws:iam::320464205386:role/MAWS-Admin. Please select a different role.
^C
Aborted!

Expected results:
Web page open to log the user back in, or the id_token is re-used to issue new STS token.

Work-around:
Removing the -r parameter for this call

[gene1wood]

This is fixed in #150 but I've not deployed an updated Pypi release yet. I'll do so in the next couple days. For now, feel free to just delete the idtoken in your cache