Migrate to angular 6.0.1 and Rxjs 6.1.0

[arnaudleclerc]

• What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)
  Migration to angular 6.0.1 and Rxjs 6.1.0

• What is the current behavior? (You can also link to an open issue here)

#132

• What is the new behavior (if this is a feature change)?

[Supamiu]

Travis build failed due to a strange timeout while fetching some dependencies.

Nice PR 👍 I was about to do the same as removing rxjs-compat is a top priority for a lot of people right now (including me).

[arnaudleclerc]

@Supamiu Thanks! Should I do anything concerning the Travis build or should I wait for anyone to restart it if possible ?

[Supamiu]

I think @ObaidUrRehman should restart the build, or test the build by him/herself, just to make sure everything is going fine.

[ObaidUrRehman]

@arnaudleclerc, Thanks for this PR.
I remember fixing the Travis issue in master. I forgot to merge it into develop. Anyway, I will take care of it in a few hours.

[ObaidUrRehman]

@arnaudleclerc, any idea why I get this error when running the demo app:

Error: (SystemJS) XHR error (404 Not Found) loading http://localhost:3000/rxjs-compat/Observable
	Error: XHR error (404 Not Found) loading http://localhost:3000/rxjs-compat/Observable
	    at XMLHttpRequest.wrapFn (http://localhost:3000/node_modules/zone.js/dist/zone.js:1218:39)
	    at ZoneDelegate.invokeTask (http://localhost:3000/node_modules/zone.js/dist/zone.js:421:31)
	    at Zone.runTask (http://localhost:3000/node_modules/zone.js/dist/zone.js:188:47)
	    at ZoneTask.invokeTask [as invoke] (http://localhost:3000/node_modules/zone.js/dist/zone.js:496:34)
	    at invokeTask (http://localhost:3000/node_modules/zone.js/dist/zone.js:1570:14)
	    at XMLHttpRequest.globalZoneAwareCallback (http://localhost:3000/node_modules/zone.js/dist/zone.js:1596:17)
	Error loading http://localhost:3000/rxjs-compat/Observable as "rxjs-compat/Observable" from http://localhost:3000/node_modules/rxjs/Observable.js
	    at XMLHttpRequest.wrapFn (http://localhost:3000/node_modules/zone.js/dist/zone.js:1218:39)
	    at ZoneDelegate.invokeTask (http://localhost:3000/node_modules/zone.js/dist/zone.js:421:31)
	    at Zone.runTask (http://localhost:3000/node_modules/zone.js/dist/zone.js:188:47)
	    at ZoneTask.invokeTask [as invoke] (http://localhost:3000/node_modules/zone.js/dist/zone.js:496:34)
	    at invokeTask (http://localhost:3000/node_modules/zone.js/dist/zone.js:1570:14)
	    at XMLHttpRequest.globalZoneAwareCallback (http://localhost:3000/node_modules/zone.js/dist/zone.js:1596:17)
	Error loading http://localhost:3000/rxjs-compat/Observable as "rxjs-compat/Observable" from http://localhost:3000/node_modules/rxjs/Observable.js

Guess its time to upgarde demo app to use angular cli.

[arnaudleclerc]

@ObaidUrRehman I managed to start the demo app without the angular-cli. I'll take a look at it and let you know. Thanks for the merge!

[arnaudleclerc]

@ObaidUrRehman I started your demo application yesterday and didn't have any problem so far. I'll assume then that you're trying to run it with the v4 of your package.

If so, your demo-app needs to have a dependency to rxjs-compat to continue working correctly. The mapping to the old rxjs/Observable and other old paths will be handled by this package. That's for the combination angular v6 + ng-drag-drop v4.

If you publish the next version of your package, this rxjs-compat will be useless and can be removed (which was the goal of this PR). For you to try, build your package and copy the javascript files of the two directives and the ng-drag-drop.service into the node_modules of your demo app (which is the same thing as installing the v6 of your package) and it should run smooth.