Hello,

Currently, there is no option to download files through an API by setting a MIME type. 

I am trying to use a bitbucket repository as a helm chart repository; Please refer to:

https://medium.com/@mattiaperi/create-a-public-helm-chart-repository-with-github-pages-49b180dbb417
https://community.atlassian.com/t5/Bitbucket-questions/Helm-repository/qaq-p/1022537#M49562

The file is being set to the wrong mime type on download, so helm when it uses it can not unpack it and has an error

`Error: gzip: invalid header`

After downloading, the file format is set to other than the actual format of the file.