Write Tests for View Model add_post_view_model.dart

[palisadoes]

The Talawa code base needs to be 100% reliable. This means we need to have 100% unittest code coverage.

We will need unittests done for all methods, classes and functions found in this file.

Any widgets referenced in this file must also have unittests done

lib/view_model/after_auth_view_models/add_post_view_models/add_post_view_model.dart

The current code coverage for this file can be found here:

• https://app.codecov.io/gh/PalisadoesFoundation/talawa?displayType=list

[AyushRaghuvanshi]

Hey, I would like to take this issue up.

[noman2002]

Our policy is to assign no more than two issues to each contributor across all repositories. This way everyone gets a chance to participate in the projects. We sometimes give exceptions for more urgent cases and sometimes we lose track, but the policy stands. You have reached your limit, please wait until your existing issues are closed before requesting more issues. You could unassign yourself from one of the other issues too.

[Dante291]

@noman2002 I can work on this.