Hyper: zoom out crashes

[cwlowder]

• [x] I am on the latest Hyper.app version
• [x] I have searched the issues of this repo and believe that this is not a duplicate

• OS version and name: Microsoft Windows 10 Version 1803 (OS Build 17134.590)
• Hyper.app version: Hyper 2.1.2
• Link of a Gist with the contents of your .hyper.js: https://gist.github.com/cwlowder/5113db7f2314bd250cef010de2f95372
• Relevant information from devtools [Violation] 'requestAnimationFrame' handler took 70ms
• The issue is reproducible in vanilla Hyper.app: Is Vanilla

Issue

When You zoom out by holding down ctrl+minus for a few seconds, hyper will freeze and then crash with the following devtool output:

[Violation] 'requestAnimationFrame' handler took 70ms

You will need to change your output scope to verbose to see it. This issue occurs with my native command line aswell if I make the shell argument empty in .hyper.js

[chabou]

Reproduced. But without holding my keys.
Hyper hangs up with a font-size below 2px. (hyperpower is slower below 4px)

I think that xterm doesn't like to have a too small font-size.

We can certainly fix it with a 5px minimum font-size

[Kacppian]

Can I pick this up?

[juancampa]

@Kacppian please do! :raised_hands:

[Kacppian]

Submitted the PR