fixed issue #11

[itai192]

this is my first commit to a public repo, so I don't know if I'm doing it right

Description

fixed issue #11

Checklist

• An issue was first created before opening this pull request
• The new code follows the contribution guidelines
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests to ensure that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[dmitryvhf]

Decline.

1. The current correct code has been broken.
2. StringPermutationTests discredited.

[dmitryvhf]

Absolutly critical code!

1. Remove(index) - remove From to End. You are drop all symbols from right.
2. String immunable. "other" object it not changed.
   Example: other = other.Remove(index, 1);
   But this bad too - immunable string operation = bad performance, memory and etc. problem.

StringPermutationTests discredited. This test case must will be fail.

var one = "dbcdefg"; var two = "dabcgfe"; Assert.True(Permutations.IsAnargram(one, two) == true);