Fix traffic_portal audit issues and remove un-needed deps

[shamrickus]

This PR fixes the 22 vulnerabilities (12 high, 3 critical) found by
npm audit. It also removes TP dependencies that are not used.

Changelogs for updates (all breaking changes are not relevant):
bootstrap-sass, es5-shim, express, font-awesome, grunt-brwoserify, grunt-html2js, grunt, json3, load-grunt-config, sass, time-grunt

Removed:
grunt-concurrent, grunt-contrib-concat, grunt-contrib-cssmin, grunt-contrib-jsmin, grunt-contrib-uglify, grunt-contrib-htmlmin, grunt-newer, grunt-contrib-jshint and grunt-wiredep

Note: t_p/app/src/package.json contains the required node_modules to run the server portion of TP. t_p/app/package.json also needs these deps for the build process even though it's not actually needed for the front end. As such the versions of these two files should always match.

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Which Traffic Control components are affected by this PR?

• Traffic Portal

What is the best way to verify this PR?

Build TP in both dev and prod mode. Verify both still work, run tests and make sure they still work. Verify npm audit returns 0 issues.

If this is a bugfix, which Traffic Control versions contained the bug?

• master

PR submission checklist

• This PR has tests
• This PR has documentation
• This PR has a CHANGELOG.md entry
• This PR DOES NOT FIX A SERIOUS SECURITY VULNERABILITY (see the Apache Software Foundation's security guidelines for details)