Add a simple project to testing/CI that builds an executable against MOAB using build system support

[Paul Wilson]

One of the features of a MOAB install is that it provides CMake and Autotools files that are included to define a variety of parameters, including INCLUDE and LIBRARY directories, for example.

The utility of these files is not tested in CI and sometimes a source of failure/bugs.

This could be mitigated by adding a small "Hello-world"-like project to CI that would build against an install of MOAB that included these configured files.

[Vijay M]

We can add a CMake build route for examples and use it as a sanity checker. Would serve a dual purpose; we already do make examples for autoconf testing but don't have an equivalent for CMake anymore. This path will use the configuration generated CMake input and build examples.

I already added this functionality to examples a while back, but it is outdated. I'll update this.

[Vijay M]

This has been addressed in PR #397. We can now use any of the examples in the source tree to test build/linkage against an installed MOAB package with either autotools or CMake.