fix bug in install trying to write last_updated, remove shims one-by-one when uninstalling apps so they aren't left around to cause strange errors when another app dir can't be deleted later down the line

bin/install.ps1

@@ -27,7 +27,7 @@ dl $zipurl $zipfile
 unzip $zipfile $dir 'scoop-master'
 rm $zipfile
 
-$null > "$currentdir\last_updated" # save install timestamp
+$null > "$dir\last_updated" # save install timestamp
 
 echo 'creating shim...'
 shim "$dir\bin\scoop.ps1"

bin/uninstall.ps1

@@ -20,6 +20,7 @@ installed_apps | % {
 
 	echo "uninstalling $app"
 	run_uninstaller $manifest $architecture $dir
+	rm_shims $manifest
 	rm_env_path $manifest $dir
 	rm_env $manifest