Need a unix-compatible release to the gallery

[vors]

This is required for PowerShell/PowerShell#2743

Current gallery version produces the following errors on unix (among others)

[-] Validate that relative path can be specified as Path parameter of Compress-Archive cmdlet 205ms
      Exception calling "Substring" with "2" argument(s): "StartIndex cannot be less than zero.
      Parameter name: startIndex"
      at line: 348 in /home/travis/build/PowerShell/PowerShell/test/powershell/Modules/Microsoft.PowerShell.Archive/Pester.Commands.Cmdlets.Archive.Tests.ps1
    [-] Validate that relative path can be specified as LiteralPath parameter of Compress-Archive cmdlet 61ms
      Exception calling "Substring" with "2" argument(s): "StartIndex cannot be less than zero.
      Parameter name: startIndex"
      at line: 360 in /home/travis/build/PowerShell/PowerShell/test/powershell/Modules/Microsoft.PowerShell.Archive/Pester.Commands.Cmdlets.Archive.Tests.ps1
    [-] Validate that relative path can be specified as DestinationPath parameter of Compress-Archive cmdlet 54ms
      Exception calling "Substring" with "2" argument(s): "StartIndex cannot be less than zero.
      Parameter name: startIndex"
      at line: 372 in /home/travis/build/PowerShell/PowerShell/test/powershell/Modules/Microsoft.PowerShell.Archive/Pester.Commands.Cmdlets.Archive.Tests.ps1

Full build log: https://travis-ci.org/PowerShell/PowerShell/builds/190414570

[SteveL-MSFT]

@anmenaga can you look into this?

[anmenaga]

Added unix-compatible release to the gallery;
Verified on PS "v6.0.0-alpha.17" on ubuntu 16.04:
Install-Module -Name Microsoft.PowerShell.Archive -Force -Scope CurrentUser