Update validator.md
Merge pull request #381 from nikolay-kozlov/patch-1

Update validator.md
Added exception for missing required parameter for find_method option as well as test
Added space for elseif's, fixed file modes
Fixed str length
Merge pull request #388 from tombooj/master

Added exception for missing required parameter for find_method option as...
Clarified how to pass sort information. 

Keys differ for ORM and MongoODM
Merge pull request #390 from adamh114/master

Clarified how to pass sort information.
Failing test for #394
Fix for #394
Merge pull request #395 from AydinHassan/bugs/unique-validator-obj-array-cast

Issue with objects being cast to array in validators
Enhancement: use exit code from run()

Necessary to be able to tell if command ran successfully or not.
Merge pull request #397 from easybiblabs/topics/fix-exitcode

Enhancement: use exit code from run()