Issue Summary

When using Windows runners, if the runner files are stored inside a folder that contains special characters (such as ç, ã, ä, ö, ü) the runner will fail to execute the step.

Steps to Reproduce

1. Create a windows runner in the repository
2. Download and unzip the runner files within a folder that has special characters, for example : test_çã
3. Execute a pipeline that uses the Windows Runner
4. The pipeline will fail with the following error : 

The argument 'C:\Users\Administrator\test_folder_AA�\atlassian-bitbucket-pipelines-runner\bin\..\temp\<runner id>\<id>\tmp\setupArtifacts8390700349208884385.ps1' to the -File parameter does not exist. Provide the path to Windows PowerShellCopyright (C) Microsoft Corporation. All rights reserved. 

Expected Results

The Windows runner should be executed successfully when inside a folder that contains special characters in its name

Actual Results

The runner fails to run and reports problems with -File-Parameter of the scripts:

tmp\setupArtifacts{...}.ps1
tmp\setupCaches{...}.ps1
tmp\powershellScript{...}.ps1
tmp\powershellAfterScript{...}.ps1

Workaround

• Move the runner folder to a path that does not contain special characters