remove redundant property val in error message
remove redundant property val in error message

For required properties, the error message is currently:

"data.name should have required property .name"

This works for other validations, where the property is present, but required is a special case that indicates the property is not there. The above message is somewhat confusing. I've simply updated the required errors to read:

"data should have required property .name"

epoberezkin/ajv,MailOnline/ajv,marbemac/ajv,MailOnline/ajv,epoberezkin/ajv,marbemac/ajv,epoberezkin/ajv