Create a Custom Setting of type Hierarchy with a checkbox in it that disables validation rules for a given user or profile and then add this condition in your validation rule.
The easiest way is to have a test setup class that covers all the validation or you can manually disable the required validation before starting the test and make it active, after the testing is finished
Check if below posts will guide you -
https://learnsf.wordpress.com/2011/05/21/disable-validation-rules-4-data-load/
http://bobbuzzard.blogspot.in/2011/11/bypass-validation-rules-from-apex.html
http://theapexhub.com/bypass-validation-rules-while-running-apex-test-class/