Update typescript

[cdeil]

I'm deploying a new version just now.

One error I'm getting is this:

$ ng build --target=production --aot=false --base-href ./

@angular/[email protected] requires typescript@'>=2.1.0 <2.4.0' but 2.5.2 was found instead.
Using this version can result in undefined behaviour and difficult to debug problems.

Please run the following command to install a compatible version of TypeScript.

    npm install typescript@'>=2.1.0 <2.4.0'

To disable this warning run "ng set --global warnings.typescriptMismatch=false".

@vorugantia - Can you please try to upgrade (maybe in the same PR where you add the package-lock.json? Maybe it would be useful to add this production build command on travis-ci at the end?