Coerce drop and dropRight n param using toInteger (#4412)

* Coerce dropRight n param using toInteger

* Coerce drop n param using toInteger

drop.js

@@ -1,4 +1,5 @@
 import slice from './slice.js'
+import toInteger from './toInteger.js'
 
 /**
  * Creates a slice of `array` with `n` elements dropped from the beginning.
@@ -25,7 +26,7 @@ import slice from './slice.js'
 function drop(array, n=1) {
   const length = array == null ? 0 : array.length
   return length
-    ? slice(array, n < 0 ? 0 : n, length)
+    ? slice(array, n < 0 ? 0 : toInteger(n), length)
     : []
 }