Upgraded all dependencies, removed node 6 & 8 from travis config

[ryanwillis]

Simple upgrades and removed the now unsupported experimentalCodeSplitting option from test.js

[Havunen]

Can we have this PR merged please? npm is throwing error when installing this plugin and rollup v2.45.2 ...

npm ERR! code ERESOLVE
npm ERR! ERESOLVE unable to resolve dependency tree
npm ERR!
npm ERR! While resolving: babel-plugin-inferno@6.1.1
npm ERR! Found: rollup@2.45.2
npm ERR! node_modules/rollup
npm ERR!   dev rollup@"^2.45.2" from the root project
npm ERR!
npm ERR! Could not resolve dependency:
npm ERR! peer rollup@">=0.66.0 <2" from rollup-plugin-uglify@6.0.4
npm ERR! node_modules/rollup-plugin-uglify
npm ERR!   dev rollup-plugin-uglify@"^6.0.4" from the root project
npm ERR!
npm ERR! Fix the upstream dependency conflict, or retry
npm ERR! this command with --force, or --legacy-peer-deps
npm ERR! to accept an incorrect (and potentially broken) dependency resolution.
npm ERR!
npm ERR! See eresolve-report.txt for a full report.

npm ERR! A complete log of this run can be found in:
npm ERR!     C:\Users\sampo\AppData\Local\npm-cache\_logs\2021-04-16T12_03_28_028Z-debug.log

I know it can be skipped but its annoying

[Havunen]

maybe node js v14 should be added here as its current LTS?

[aravindvnair99]

@ryanwillis Could you please add this as well?

[ryanwillis]

Done.

[ryanwillis]

@TrySound any input?