Added test for the jsmin filter.
Added test for the jsmin filter.

JDeuce/webassets,glorpen/webassets,scorphus/webassets,scorphus/webassets,0x1997/webassets,john2x/webassets,heynemann/webassets,aconrad/webassets,glorpen/webassets,wijerasa/webassets,florianjacob/webassets,heynemann/webassets,heynemann/webassets,glorpen/webassets,JDeuce/webassets,aconrad/webassets,john2x/webassets,aconrad/webassets,wijerasa/webassets,florianjacob/webassets,0x1997/webassets