Not compatible with eigen5

[micwoj92]

When building against eigen 5.0.1, following error appears:

In file included from /usr/include/eigen3/Eigen/Core:22,
                 from /usr/include/eigen3/Eigen/Dense:1,
                 from src/Image.cpp:32:
/usr/include/eigen3/Eigen/src/Core/util/Macros.h:749:2: error: #error Eigen requires at least c++14 support.
  749 | #error Eigen requires at least c++14 support.
      |  ^~~~~

This is a breaking change, noted in release notes:
https://gitlab.com/libeigen/eigen/-/blob/master/CHANGELOG.md?ref_type=heads#breaking-changes

Seems to work with c++14
sed -e 's/c++11/c++14/g' -i setup.py
test suite passes:
=========== 751 passed, 1 skipped, 237 warnings in 257.58s (0:04:17) ===========
Skipped test:

test_photon_array.py::test_dcr_angles SKIPPED (Unable to import
astroplan)                                                               [ 68%]

[rmjarvis]

Thanks for the FYI. Seems like it shouldn't be a problem to update the build to require c++14. I don't think there are any systems left that can't handle that.

[rmjarvis]

Done. Version 2.8.3 uses c++14. Let me know if you still see any issues with Eigen 5.

[micwoj92]

Thanks for quick fix, I'll sure report some more issues if I find them