"Arguments" collapse while Step Over is used (Debug)

[lmazuel]

Environment data

VS Code version: 1.18.1
Python Extension version: 0.8.0
Python Version: 3.5.1
OS and version: Windows falls update

Actual behavior

In the "Variables" pan, the "Arguments" section collapse each time I click "Step Over", whatever it was openned or not.

Expected behavior

If "Arguments" is open, keep it opened. IOW, keep the state and don't collapse when I Step Over.

Steps to reproduce:

• Debug anything
• Open Arguments in the Variables section
• Do a Step Over
• Arguments has been collapsed.

Screen shot to be sure I'm clear:

Exact context: pytest debugging from the "Debug Test" mini-button top of the test name.

[DonJayamanne]

Duplicate of #49