Lots of updates

This is now using the latest version of EPPlus. Unit tests are updated and passing, if you hit problems, please open an issue. You can rollback to an older version from the PowerShell Gallery if you are blocked.

Unit tests were updated and fixed
"Set-WorksheetProtection" is now switched on
Made a change to make Set-Excel range more friendly when Auto Sizing on non-windows platforms
Fixed - Windows only tests don't attempt to run on non-windows systems
Tests based on Get-Process don't attempt to run if <20 processes are returned
If $env:TEMP is not set (as will be the case on Linux)
Join-Path if used so paths are built with / or with \ as suits the OS where the test is running.
Excel Sparklines now supported, check out the examples SalesByQuarter and Sparklines.