Fix paths

.appveyor/InstallWindump.ps1

-wget https://github.com/hsluoyz/WinDump/releases/download/v0.1/WinDump-for-Npcap-0.1.zip -UseBasicParsing -OutFile .\npcap.zip
+wget https://github.com/hsluoyz/WinDump/releases/download/v0.2/WinDump-for-Npcap-0.2.zip -UseBasicParsing -OutFile $PSScriptRoot"\npcap.zip"
 Add-Type -AssemblyName System.IO.Compression.FileSystem
 function Unzip
 {
@@ -7,6 +7,6 @@ function Unzip
     [System.IO.Compression.ZipFile]::ExtractToDirectory($zipfile, $outpath)
 }
 Unzip $PSScriptRoot"\npcap.zip" $PSScriptRoot"\npcap"
-Remove-Item ".\npcap.zip"
-Move-Item -Force ".\npcap\x64\WinDump.exe" "C:\Windows\System32\windump.exe"
-Remove-Item ".\npcap" -recurse
\ No newline at end of file
+Remove-Item $PSScriptRoot"\npcap.zip"
+Move-Item -Force $PSScriptRoot"\npcap\x64\WinDump.exe" "C:\Windows\System32\windump.exe"
+Remove-Item $PSScriptRoot"\npcap" -recurse