v0.2.2

PhysicalConstants v0.2.2

Diff since v0.2.1

Closed issues:

• Unexpected error in runtime: StackOverflowError() (#17)
• how to extract the numerical part from a physical constant (#21)

Merged pull requests:

• Move CI to GitHub Actions (#18) (@giordano)
• Upgrade Documenter to v0.27 (#20) (@giordano)
• Bump version for Roots. (#22) (@hurak)