version bump package json

[maxxcrawford]

• Add package-lock.json to tracked files
• Bump version number to 8.1.1

Developer note: when installing via $ npm install, I get a ERESOLVE overriding peer dependency error.

ERESOLVE overriding peer dependency
While resolving: webextensions-api-fake@1.3.0
Found: sinon@7.5.0
node_modules/sinon
  dev sinon@"^7.5.0" from the root project
  2 more (sinon-chai, webextensions-api-mock)

Could not resolve dependency:
peer sinon@"^8.1.1" from webextensions-api-fake@1.3.0
node_modules/webextensions-api-fake
  webextensions-api-fake@"^1.2.0" from webextensions-jsdom@1.4.1
  node_modules/webextensions-jsdom

Conflicting peer dependency: sinon@8.1.1
node_modules/sinon
  peer sinon@"^8.1.1" from webextensions-api-fake@1.3.0
  node_modules/webextensions-api-fake
    webextensions-api-fake@"^1.2.0" from webextensions-jsdom@1.4.1
    node_modules/webextensions-jsdom

I was able to resolve by running $ npm install --legacy-peer-deps.