nimble refresh out of memory on Appveyor
This may be related to https://github.com/nim-lang/nimble/issues/352 which is on Arch.

I get reproducible out of memory error on Appveyor: https://ci.appveyor.com/project/mratsim/arraymancer/build/27

The offending commit https://github.com/mratsim/Arraymancer/commit/cf1c09b89faecd3868576a1a32113b1b4267e6b7 just removes `installDirs = @["src"]` from my package.nimble file.

Build before that commit did not have such an issue: https://ci.appveyor.com/project/mratsim/arraymancer/build/20