Addjusted appveyor.yml file (cp command now used with powershell)

Author: gizmocuz

appveyor.yml

@@ -10,8 +10,8 @@ build_script:
 - '7z x WindowsLibraries.7z > NUL:'
 - cd ..
 - msbuild msbuild\domoticz.sln /p:Configuration=Release /verbosity:minimal /logger:"C:\Program Files\AppVeyor\BuildAgent\Appveyor.MSBuildLogger.dll"
-- cp appversion.h version_windows_x86.h
-- cp History.txt history_windows_x86.txt
+- ps: cp appversion.h version_windows_x86.h
+- ps: cp History.txt history_windows_x86.txt
 - '"C:\Program Files (x86)\Inno Setup 5\ISCC.exe" msbuild\WindowsInstaller\DomoticzSetup.iss'
 - msbuild msbuild\package.proj