Don't depend on 2 lodashes

[bhousel]

followup from #4372 (comment)

We use lodash (CommonJS) in a few of our build scripts, but we now use lodash-es (ES6) in the main iD code. It seems dumb to install lodash twice, so we have 2 options:

1. Eliminate use of lodash from the build scripts? The build scripts need to run in node 4 and up and we don't use lodash that much.
2. Find a way to require the es6 lodash-es library from a node script. @std/esm may offer some way forward but I couldn't get it to work after playing with it for an hour or so. It's only released a few weeks ago, so we should wait and see if it improves.

[Semigradsky]

3. Add babel (for running build scripts in node 4 and using cool es2015+ features) and babel-plugin-lodash (for eliminate use paths in imports).

@bhousel? I can help if you agree to this.

[bhousel]

Add babel (for running build scripts in node 4 and using cool es2015+ features) and babel-plugin-lodash (for eliminate use paths in imports).

I'd really prefer not to need to transpile the build scripts or introduce a babel dependency. These scripts really don't use much lodash at all, so it should be possible to replace whatever they do with traditional ES5 features.

[DzikowskiW]

@bhousel I worked on the issue today. I was able to set up @std/esm to work along with build scripts, which led to removing lodash dependencies from the build scripts.

However, many of the tests that run in PhantomJS depend on the original lodash (_.map, _.clone, _.isEqual, _.extend, _.reduce, _.find, _.intersection). If you look at test/index.html there is a link to lodash. How do you want to handle that? Should we have a separate file with helper functions for tests, or should we try to rewrite the tests not to use any of these functions?

[bhousel]

@DzikowskiW good question... Those functions seem like ones we could do without.. If you submit a PR to deal with the build scripts, I'll eliminate lodash from the tests.

[bhousel]

I'll eliminate lodash from the tests.

This was done!

Going forward, no lodash in tests, plz thx. All the tests should run in all of iD's supported browsers -
you can test this by starting a local server and browsing to localhost:8080/test/

Automated testing currently runs in PhantomJS 2.1 - which is conveniently about the same level of oldness as IE11. 😭

This means:

• No ES6
• No Object.assign or Object.values
• I added a polyfill to spec_helpers.js for Array.find()

[HolgerJeromin]

Perhaps you can replace phantomjs with
https://developers.google.com/web/updates/2017/06/headless-karma-mocha-chai