NekMesh unit tests

Issue/feature addressed

NekMesh was void of any form of unit testing.

Proposed solution

Using the existing boost testing framework to add unit tests to NekMesh and provide a few examples to build on.

Implementation

Following the existing unit testing for other parts of Nektar++, a NekMesh directory was added to library/UnitTests and an example test was provided.

Tests

The first example test is the constructor for a Tetrahedron. More to follow.

Suggested reviewers

@dmoxey

Notes

This is only the start of building up unit testing in NekMesh so the tests are still few and far between.

Checklist

• Functions and classes, or changes to them, are documented.
• User guide/documentation is updated.
• Changelog is updated.
• Suitable tests added for new functionality.
• Contributed code is correctly formatted. (See the contributing guidelines).
• License added to any new files.
• No extraneous files have been added (e.g. compiler output or test data files).