Add context example for non-integer input

Add catch for non-integers

Ensure @other_divisors is not modified on invalid input

Touchup spacing, indentation

Ensure @other_divisors remains empty when the @n is prime

Add tests for default values

Add context example for finding primes in a range

Expand EvalPrime to find all primes in a given range

Add example of range with no primes
Merge github.com:FluffyCode/RubyCode
Ensure primes_in_range is reset to an empty array before evaluating a range
Reset primes_in_range before evaluation