Add Appveyor support - Windows testing about gzip.jl

[hustf]

The travis.yml file excludes testing on Windows. It takes a while to discover these things.

Non-tested code here may affect, for example, users of packages
Codecs
WinRPM
ZipFile
ZLib
Gadfly
ZMQ
Nettle
HDF5
TestImages
...and the list goes on. This package really ought to work and be tested on Windows I think.

[kmsquire]

Hi @hustf, thanks for your interest in this package. Recently, LibZ.jl was released, which is meant to replace both GZip.jl and Zlib.jl. As that package gets more traction, it's likely that both of these latter packages will be deprecated. I encourage you to check out LibZ.jl and see if it fits your needs.

[hustf]

Oh, good, because this was getting pretty difficult:
ccall(:dup, Int32, (Int32,) fd) on GZip.jl:278
gives
could not load symbol "dup" on Windows, not on Mac.

I´ll make a pull request on what I have, though it´s a dead end.

[hustf]

That´s done. Pull request #41. The updated travis would make Windows tests fail.

[kmsquire]

@simonster made the comment in #41 that Windows isn't supported on Travis. A little googling suggests that Windows support is actually moving forward there, but until it becomes fully supported and common, the Julia community has settled on Appveyor as the Windows solution for testing.

So, @hustf, if you wanted, this issue could be retitled to add Appveyor support. (Notably, Libz.jl doesn't have Appveyor support either.)

[hustf]

Thanks for the patience, @simonster and @kmsquire. #41 shouldn't, of course, be pulled in as it is. In my repo, 16 out of 64 packages have Appveyor.yml so far.

The Compat package seems to be an exemplary template. Output here: https://ci.appveyor.com/project/quinnj/compat-jl/branch/master