Bump Dependencies

[github-actions]

> ungit@1.5.9 bumpdependencies /home/runner/work/ungit/ungit
> ncu --upgrade --reject bootstrap

Upgrading /home/runner/work/ungit/ungit/package.json

 @primer/octicons      ~10.0.0  →   ~10.1.0 
 diff2html             ~3.1.11  →   ~3.1.12 
 getmac                ~5.13.0  →   ~5.15.0 
 lodash               ~4.17.19  →  ~4.17.20 
 open                   ~7.1.0  →    ~7.2.0 
 browserify            ~16.5.1  →   ~16.5.2 
 electron               ~9.1.2  →   ~10.1.0 
 electron-packager     ~15.0.0  →   ~15.1.0 
 eslint                 ~7.5.0  →    ~7.7.0 
 eslint-plugin-mocha    ~7.0.1  →    ~8.0.0 
 mocha                  ~8.1.0  →    ~8.1.2 
 npm-check-updates      ~7.0.2  →    ~7.1.1 
 prettier               ~2.0.5  →    ~2.1.1 
 superagent             ~5.3.1  →    ~6.0.0 

Run npm install to install new versions.

[campersau]

The biggest change is

 electron               ~9.1.2  →   ~10.1.0 

which also increases the size of the electron packages by ~8 MB.