Moose/Plot.t fails on Windows (appveyor)

[akhuettel]

[00:11:53] t/pod.t ....................... skipped: Test::Pod required for testing POD
[00:11:54] Name "PDL::Graphics::Gnuplot::gp_version" used only once: possible typo at t/Moose/Plot.t line 29, <DATA> line 207.
[00:11:54] PDL::Graphics::Gnuplot: ERROR: the gnuplot backend issued an error:
[00:11:54] ^
[00:11:54]          cannot open file; output not changed
[00:11:54]          line 0: util.c: Invalid argument
[00:11:54]  at C:/strawberry/perl/site/lib/PDL/Graphics/Gnuplot.pm line 7847.
[00:11:54]      PDL::Graphics::Gnuplot::_checkpoint(PDL::Graphics::Gnuplot=HASH(0x55a5de0), "main", HASH(0x58d3e78)) called at C:/strawberry/perl/site/lib/PDL/Graphics/Gnuplot.pm line 3202
[00:11:54]      PDL::Graphics::Gnuplot::plot(undef, undef, "with", "points", PDL=SCALAR(0x5587e58), PDL=SCALAR(0x55895a8)) called at C:\projects\lab-measurement\Measurement\lib/Lab/Moose/Plo
t.pm line 190
[00:11:54]      Lab::Moose::Plot::_plot(Lab::Moose::Plot=HASH(0x58cdc50), HASH(0x55880b0), HASH(0x53db600), ARRAY(0x55a98c8), "plot") called at C:\projects\lab-measurement\Measurement\lib/La
b/Moose/Plot.pm line 223
[00:11:54]      Lab::Moose::Plot::plot(Lab::Moose::Plot=HASH(0x58cdc50), "curve_options", HASH(0x53db600), "data", ARRAY(0x55a98c8)) called at t/Moose/Plot.t line 55
[00:11:54] t/Moose/Plot.t ................ 
[00:11:54] C:\Users\appveyor\AppData\Local\Temp\1\D4QkBIpyvP\low_level_plot.txt
[00:11:54] No subtests run 
[00:11:55] Useless use of anonymous list ([]) in void context at t/Moose/DataFile/Gnuplot.t line 108, <DATA> line 207.
[00:11:55] cannot unlink file for C:\Users\appveyor\AppData\Local\Temp\1\rjhO_LADMY\gnuplot_001\META.yml: Permission denied at C:/strawberry/perl/lib/File/Temp.pm line 784.
[00:11:55] cannot remove directory for C:\Users\appveyor\AppData\Local\Temp\1\rjhO_LADMY\gnuplot_001: Directory not empty at C:/strawberry/perl/lib/File/Temp.pm line 784.
[00:11:55] cannot remove directory for C:/Users/appveyor/AppData/Local/Temp/1/rjhO_LADMY: Directory not empty at C:/strawberry/perl/lib/File/Temp.pm line 784.

[amba]

I think this is a P::G::G problem:
PDLPorters/PDL-Graphics-Gnuplot#65

[amba]

Fixed: PDLPorters/PDL-Graphics-Gnuplot#67