Add support for encrypted SSH keys + MySQL socket

[benface]

First of all, thank you for open sourcing this. I didn't realize I needed such a tool until I tried it.

This PR adds two features that I personally needed and that can hopefully benefit others:

• It adds support for encrypted SSH keys by asking the user to enter the key's passphrase when it is needed. (Add support for encrypted ssh keys #11)
• It adds support for a DB_SOCKET environment variable which is notably needed when using MAMP for local development; see this answer on StackExchange.

Feedback welcome! Thank you :)

[ben-rogerson]

Hey Ben, thanks so much for the new features!
From the looks of things you added the passphrase to the SSH session task and I'm thinking it might also be good to add it to some of the other tasks.
I'm away on holidays until the start of January so I'll plan on rolling it into a new release then.

[benface]

Thanks @ben-rogerson! I appreciate you taking the time to look at it.

From the looks of things you added the passphrase to the SSH session task and I'm thinking it might also be good to add it to some of the other tasks.

I think I added it to every task by modifying the sshConnect function? I could be wrong though.

[ben-rogerson]

That sounds about right, ill have to take a better look. Ill be in touch 👍

[ben-rogerson]

So turns out this is quite a task as there are a few different types of connection functions used throughout the other tasks. Not sure which route I'll take on this yet, but at the very least I'll be able to put through the DB_SOCKET feature.

[benface]

@ben-rogerson Can you give me an example of a function that doesn’t support encrypted keys in this PR? I was pretty sure I tested everything, but maybe I forgot some?

[ben-rogerson]

Take a look at the work on the 1.6.0 branch: https://github.com/burgerbuds/swiff/commits/release/v1.6.0
It was a while back now, I can't remember which functions needed updates - sorry!