Fix MATLAB tests

[ludvigak]

Simple fixes to get rid of errors in Matlab test suite

• Add Chebfun as submodule dependency
• Removed section breaks that split up tests
• Removed hardcoded file path
• Set default edge color in @surfer/plot to black (?)
• Create ndeg=1 in test_surf_lap. It seemed like the right value.

NOTE: There are more hard-coded paths in demo/ that point to ~/git/fmm3dbie and ~/git/surface-hps

[ludvigak]

To test the branch you'll have to run git submodule update --init --recursive to get the new submodule checked out

[ahbarnett]

grepping matlab directory I only see chebpts and barymat used from chebfun pkg - if that's all, can't we remove chebfun as a dependency?

[ludvigak]

First I tried copying in only legpts and chebpts, but the latter called chebtech1, at which point I gave up and pulled in all of chebfun. You can probably untangle the dependencies with some patience though.

[mrachh]

We are on it to remove those dependencies. Thanks for these catches Ludvig, we can merge them in, once the dependencies are removed.

[ahbarnett]

I forgot legpts. Yes, keep chebfun as dependency for next week.

[mrachh]

Hi Ludvig, can you remove the chebfun dependency and update the pull request? I think I should've successfully removed those dependencies..

[ludvigak]

Had to do a few fixes, but now all tests pass without Chebfun