Upgrade to latest Angular

[CloudNiner]

This will require updating a few or most dependencies in lockstep, if those dependencies are built with the Angular CLI.

• Angular CLI should be updated to 1.6+ to support Angular 5 builds
• ng2nouislider should be updated to 1.7.5+ to support Angular 5

Other packages may need to be updated as well.

Requires azavea/climate-change-components#50

[CloudNiner]

See #262 for details about recent issues with Angular builds

[fungjj92]

Do we want to upgrade to Angular 5? Angular 4 is the only known LTS.
https://github.com/angular/angular/blob/master/docs/RELEASE_SCHEDULE.md

[CloudNiner]

Huh. Didn't know this table existed. I don't think we want to update to Angular 5 immediately, this is just here as a placeholder in case it becomes necessary for some feature (which I'd like to avoid as much as possible)

LUL at one year LTS for a javascript project...

[fungjj92]

Omg I just saw the v4 End LTS date is Oct 2018! Tragic.

[jcahail]

Most likely, we should just upgrade to Angular 6.

[CloudNiner]

Things to watch out for during upgrade:

• Angular 6: RxJS v6 migration
• Angular 5: Replace API token injection with HTTP interceptors

[maurizi]

The version of Angular we're using (4) is now past the support date.