Senza disregard "NoEcho" attribute for parameters when creating default stack description

[alterrebe]

Senza creates a default stack description (components/configuration.py, method get_default_description() ) by concatenating the stack name with all the parameters values used to create the stack. The values are shown in clear text even if a particular parameter is defined as NoEcho, so the behavior defeats the purpose of the NoEcho attribute.

Senza should honor the NoEcho attribute and replace such parameters' values with **** in the same way as AWS console does.

[alterrebe]

A temporary workaround is to provide an explicit stack description by duplicating the description clause both inside SenzaInfo and on the top level:

SenzaInfo:
   StackName: foo
   Description: some description
   ...

Description: same description

SenzaComponents:
   ...

It prevents Senza from generating the default description. A drawback is that we don't see other parameters values in the stacks list.

[hjacobs]

Honoring NoEcho sounds reasonable.