String Calculator

1. Create a simple String calculator with a method int Add(string numbers)
   2. Start with the simplest test case of an empty string and move to 1 and two numbers
   3. Remember to solve things as simply as possible so that you force yourself to write tests you did not think about
   4. Remember to refactor after each passing test
2. Allow the Add method to handle an unknown amount of numbers
3. Allow the Add method to handle new lines between numbers (instead of commas).
   1. the following input is ok:
   2. the following input is NOT ok:
   3. Make sure you only test for correct inputs. there is no need to test for invalid inputs for these katas
4. Allow the Add method to handle a different delimiter:
   1. to change a delimiter, the beginning of the string will contain a separate line that looks like this:delimiter]\n[
   2. the first line is optional. all existing scenarios should still be supported
6. Numbers bigger than 1000 should be ignored, so adding 2 + 1001 = 2
7. Delimiters can be of any length with the following format:delimiter]\]\n12***
8. Allow multiple delimiters like this:delim1][delim2]\][%]\n1
9. make sure you can also handle multiple delimiters with length longer than one char