Add Heapsort tests

[leto]

We could use some actual tests in t/Heapsort.t

[NielsKornerup]

I currently do not know any Perl, but would be willing to learn enough to make some Heapsort tests. Would it be viable to generate random lists and compare the result to the sort function? I see that you already have tests for that.

[leto]

Just to clarify, this issue requires Perl, not Go.

Basically you can convert the GSL heapsort tests from C to Perl:

http://git.savannah.gnu.org/cgit/gsl.git/tree/sort/test_heapsort.c

You don't have to support all the options/tests that they have. Just having at least one test for each heapsort function is good enough.

[hchienjo]

I have been assigned this module as part of the PRC and I would like to work on this issue.

[leto]

@hchienjo sounds great! Are you able to clone the Math::GSL git repo and build the code + run the tests? If so, do they pass? You will need SWIG 2.0.8 or greater (which is not a dependency if you just install the CPAN module, which has generated code in it). Let me know if you need help.

[hchienjo]

I have already cloned the repo, was waiting for a go ahead sign from you before I really get into work.

[leto]

@hchienjo ok, go for it!

[hchienjo]

I have decided to start small with this pr #138 as I go over the use of swig and especially type conversions. I am still interested in fixing this but it will take more time as I work on the type conversions. I had thought that in order to fix this issue, only tests are required but I see that I will need to work on Heapsort.i (correct me if I am wrong). I will ping you with more details as soon as I begin add typemaps for void [] and compiling.