Security - Upgrade `@angular/cli`

[azerella]

In order to resolve the security warning on this repo we need to upgrade the @angular/cli package.

There are breaking changes going from 1.6.8 -> 7.3.1 not just for this package but basically all angular packages. Updating the angular.json file for example is required.

[TamjidTayeb]

Upgraded Angular

[azerella]

@TamjidTayeb I'm going to reopen this issue as I can't see a PR that resolves this problem. Only consider something done once the changes are in master, #79 is into develop

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