Add a "print version" option

[dpopp07]

This came up while looking at an issue with Allen - there was no obvious way to see which version he had installed locally. Since most CLI tools use the -v option to print the version, I decided to add this.

There was previously a -v arg for printing validator file names but that was a debug tool I made for myself and I can't imagine any users would use that, plus we are still in 0.x so we can make breaking changes 😏

In this PR...

• The -v option is updated to print the version
• The print validator version is changed to -p
• The logic for turning off coloring is simplified with a ternary operator
• The README is updated with new option and also correct some outdated statements (the npm --save option is now deprecated)
• The appropriate option handler test is updated

[SirSpidey]

oh sure. blame me.

[mkistler]

Looks good! 👍