Update config when changing profile

[garar]

Hi!

aws cli keeps account settings in two files: ~/.aws/credentials and ~/.aws/config. When you update profile, you only update credentials files. It would be good if you could also update config file, so my default region would change.

[kmendler]

Hi! Can I pick up this issue?

[ror6ax]

@kmendler Sorry for late answer! I will have a look at your pull request tonight!