Support symbolic link in path

[freak4pc]

Describe the bug
If path to a file involves a symbolic link, the file is not found

Version

• V1
• V2

Environment

• self-hosted
• Linux
• Windows
• Mac

How to reproduce

Running as

- name: Archive production artifacts
      uses: actions/upload-artifact@v2
      with:
        name: Store executable
        path: .build

Works, and the big zip file looks as follows:

When trying this, though:

- name: Archive production artifacts
      uses: actions/upload-artifact@v2
      with:
        name: Store executable
        path: .build/release/prism.exe

It fail, since release is actually a symlink to to x86_64-unknown-windows-msvc/release.

Using .build/x86_64-unknown-windows-msvc/release/prism.exe directly does work.

Notice also that the downloaded ZIP contains a double copy of this since the symlink is resolved as a regular uploaded file and not counted as a symbolic link (This seems to be related to #93)

[konradpabjan]

Closing as a dup of #92 and #93