Ensure we lowercase all tokens before testing against the stopwords, and reduce the number of conditionals per function call.
Ensure we lowercase all tokens before testing against the stopwords, and reduce the number of conditionals per function call.

walkingdoctors/natural,karimsa/natural,NaturalNode/natural,PTaylour/natural,levy5674/natural,polymaths/natural,moos/natural,Hugo-ter-Doest/natural,kjhenner/natural,itamayo/natural,mcanthony/natural,ahmedshuhel/natural,mamaral/natural,PMSI-AlignAlytics/natural,dpraimeyuu/natural