Tweaks to run_docker script for windows bash compatibility

[esune]

Fixes compatibility issues with the run_docker script when running in bash under windows.

Tested with:

• GNU bash, version 4.4.23(1)-release (x86_64-pc-msys)
• GNU bash, version 4.4.20(1)-release (x86_64-pc-linux-gnu) (WSL in Windows 10)

[codecov-io]

Codecov Report

Merging #357 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #357   +/-   ##
=======================================
  Coverage   89.24%   89.24%           
=======================================
  Files         236      236           
  Lines       11187    11187           
=======================================
  Hits         9984     9984           
  Misses       1203     1203

[andrewwhitehead]

Please update demo/run_demo as well

[esune]

@andrewwhitehead done! Sorry I missed that.

I also added run_demo to .gitattributes as the line endings were being switched to crlf in Windows (everything in the scripts folder is already handled correctly).