Refactor Prime_number_check

[CiganOliviu]

I am creating a pull request for...

• [ ] New algorithm
• [x] Update to an algorithm
• [x] Fix an error
• [x] Other - Describe below

• First I found a problem in the naming convention of the function. When I was writing the tests I found that the name is making me think that the function should return true if the number is prime. It returned false in reality which bothers me. So I changed the name in a more communicative one.

• I've changed the algorithm so that will avoid using the break keyword.

• I've changed the algorithm because it's returning that 1 is a prime number when it's not.

• There is also some refactoring which can be reflected by the code base itself.