(IAC-1414) Throw error in range() function when step size invalid

Prior to this commit, on Ruby 2.7, the range() method would NOT
throw an ArgumentError exception if it was passed an invalid value as the
step size (3rd arg). Instead, it would return an array of size
1,000,000 with repeated integer values of the 2nd arg.

The function invokes Ruby's in built range method and step to
define a step size to increment / decrement by and then passes the
output to first, limiting to the first 1,000,000 values.

On Ruby < 2.7, step would throw an ArgumentError if the step
size passed was 0:

1..2).step(0).first(1_000_000).to_a
Traceback (most recent call last):
        5: from ~/.rvm/rubies/ruby-2.5.8/bin/irb:11:in `<main>'
        4: from (irb):7
        3: from (irb):7:in `first'
        2: from (irb):7:in `each'
        1: from (irb):7:in `step'
ArgumentError (step can't be 0)

However, on Ruby 2.7, the step method returns an Enumerator that
will then subsequently generate an Array of the size specified when
passed to first, made up of the 2nd arg value (last):

(1..2).step(0).first(10).to_a
 => [1, 1, 1, 1, 1, 1, 1, 1, 1, 1]

This is an issue, as the 3rd arg is passed to to_i, which then
becomes the step size. For any values that cannot be converted to
a positive / negative (or legit 0) Integer, a 0 is returned.

This commit will perform a check on the value of step and throw
an ArgumentError if it is not zero.