Added quiet flag to hide progress animation during install

[asmeili]

Adds a new flag to the install command which hides the progress animation from stdout.

Issue: #14

[cmcgee1024]

Thanks for your contribution.

There are other progress animations, such as self-update. I wonder if this should be abstracted out to one of the GlobalOptions in Swiftly.swift. But then, quiet is the opposite of verbose, which is already there so there will need to be some consideration about the interaction of the two. Perhaps they can be unified into a single flag and enum.

In terms of the progress animation. It already appears to be able to detect whether it is running in a terminal context or not, and falls back to a line-oriented output. Are you wanting it to display no progress at all when this option is set? Maybe the detection isn't very effective and leaks escape codes in certain logs? Any other things that should be quieted in the various swiftly commands when the flag is set?

[asmeili]

Hi, thanks for taking a look.

During implementation I also considered making this a global flag, however I'd love to hear your input on how this should behave for commands that do not make use of this flag. Is there a way to opt-in this flag only for a particular set of commands without duplicating the flag?

I agree with the verbose flag. Maybe a simple log flag that can either be set to verbose or quiet?

From my understanding of DynamicProgressAnimation from TSCBasic it looks like, for a terminal output stream, it'll use the animation style. It will then display the progress by sending the output multiple times, which the issuer creator does not seem to want. Instead it looks like they wanted a way to silence this progress output entirely and only have an output of either success or error.