Removed DataType condition that breaks $exists lookups in mongoDB

[jsheely]

I'm not entirely sure what this DataType(val) check is even needed for.

But in a query like this:

http://localhost:4001/api/products?filter[where][tags][exists]=true

This method will return: "[object, Object]" instead of using the actual object {exists: true} which will get converted later in the buildWhere in mongoDB to {$exists: true}

[slnode]

Can one of the admins verify this patch? To accept patch and trigger a build add comment ".ok\W+to\W+test."

[jsheely]

This is related to this issue: strongloop/loopback#1009 for mongoDB

[jfurie]

+1

[ssh24]

@jsheely Looks like you had this branch on your old fork which you deleted. If you look at the top it says:
jsheely wants to merge 2 commits into strongloop:master from unknown repository

Closing this PR for that reason. Please create a new one and assign me to it so that I can take a look.