Pull Request: C3_Rami_570_Add_Contest_Problems_3.23

Issue #570 
Reviewers: @Ahmed-Moataz @Rania-Abdel-Fattah @ranaelnagar @Ahmed-Atef @ahmed93

For scenario reviewers, visit 'c_problems/new' while signed in as lecturer. If you get a signed in successfully notice, it's because that message wasn't shown in the previous view and was kept in the flash buffer.

<h2>Success Scenarios</h2>
<ul>
 <li>The lecturer or TA submits the contest problem details using the form.</li>
 <li>The problem is saved in the database for use in future contests.</li>
</ul>
<h2>Failure Scenarios</h2>
<ul>
 <li>Error displayed when empty title sent.</li>
 <li>Error displayed when empty description sent.</li>
 <li>Error displayed when time limit is empty or non numeric.</li>
</ul>