Add Andris Mednis (@andrismednis) as a contributor

Fix README file

Merge pull request #6 from mpsdantas/master

CUID and SLUG Validations

Merge pull request #6 from mpsdantas/master

CUID and SLUG Validations

Add go.mod. Death to GOPATH!

Fixed data races.

Problem spotted by Thomas Hopkins who submitted a pull request which I implemented slightly differently.

Completed README file.

Completed README file.