I think it is a good idea to consider dropping of support of node versions that are less than v12. I say that because some of spectacle dependencies are using only node v12 or higher.

1, this branch works

I can confirm. For reference, here are the steps I used for testing:

1. $ git clone https://github.com/sourcey/spectacle
2. $ cd spectacle/
3. $ git remote add MatheusCamelucci https://github.com/MatheusCamelucci/spectacle
4. $ git fetch MatheusCamelucci
5. $ git checkout fix/dependencies
6. $ npm install

   npm WARN read-shrinkwrap This version of npm is compatible with lockfileVersion@1, but package-lock.json was generated for lockfileVersion@2. I'll try to do my best with it!
   
   > [email protected] install /home/waldyrious/.local/src/spectacle/node_modules/node-sass
   > node scripts/install.js
   
   Downloading binary from https://github.com/sass/node-sass/releases/download/v6.0.1/linux-x64-83_binding.node
   Download complete  ] - :
   Binary saved to /home/waldyrious/.local/src/spectacle/node_modules/node-sass/vendor/linux-x64-83/binding.node
   Caching binary to /home/waldyrious/.npm/node-sass/6.0.1/linux-x64-83_binding.node
   
   > [email protected] postinstall /home/waldyrious/.local/src/spectacle/node_modules/node-sass
   > node scripts/build.js
   
   Binary found at /home/waldyrious/.local/src/spectacle/node_modules/node-sass/vendor/linux-x64-83/binding.node
   Testing binary
   Binary is fine
   npm WARN optional SKIPPING OPTIONAL DEPENDENCY: [email protected] (node_modules/fsevents):
   npm WARN notsup SKIPPING OPTIONAL DEPENDENCY: Unsupported platform for [email protected]: wanted {"os":"darwin","arch":"any"} (current: {"os":"linux","arch":"x64"})
   
   added 627 packages from 453 contributors and audited 630 packages in 12.531s
   
   44 packages are looking for funding
   run `npm fund` for details
   
   found 16 vulnerabilities (4 low, 1 moderate, 11 high)
   run `npm audit fix` to fix them, or `npm audit` for details
   

7. $ bin/spectacle.js -d -l test/fixtures/cheese.png test/fixtures/cheese.yml

   Running "sass:foundation_scss" (sass) task
   
   Running "concat:foundation_css" (concat) task
   
   Running "sass:scss" (sass) task
   
   Running "concat:css" (concat) task
   
   Running "cssmin:minify" (cssmin) task
   >> 2 files created. 148 kB → 118 kB
   
   Running "concat:js" (concat) task
   
   Running "uglify:js" (uglify) task
   >> 1 file created 6.8 kB → 2.96 kB
   
   Running "copy:logo" (copy) task
   Copied 1 file
   
   Running "clean:html" (clean) task
   >> 1 path cleaned.
   
   Running "compile-handlebars:compile" (compile-handlebars) task
   
   Running "predentation" task
   
   Running "prettify:index" (prettify) task
   >> File "/home/waldyrious/.local/src/spectacle/public/index.html" prettified.
   
   Running "connect:server" (connect) task
   Started connect web server on http://localhost:4400
   
   Running "watch" task
   Waiting...
   ^C
   

8. Open http://localhost:4400/ in the browser

(Note: this was using Node.js v14)

Thanks for this, nice to get those deps updated :)