Merge pull request scipp#1240 from scipp/Update-release-notes-for-0.4

Update release notes prior to 0.4

Merge pull request scipp#1037 from scipp/histogram-scalar-fix

Fix histogram to not drop scalar coords

Actually fix OS X deploy pipeline

Merge pull request scipp#792 from scipp/fix-from_mantid

Fix from_mantid

Fix tag regex for release builds

Merge pull request scipp#553 from scipp/cleanup

Move source into separate files

Try to fix travis stage config for releases.

Merge pull request scipp#186 from mantidproject/demo_part3_solution

Demo part3 solution