Add Test for GetPossibleConfig Function

[anilswm]

Function GetPossibleConfig Defined in
https://github.com/LoginRadius/csharp-password-hash/blob/master/csharp-password-hash/csharp-password-hash/PasswordHashing.cs

[priyanka1111]

@anilswm can i take up this .

[SRvSaha]

@anilswm @priyanka1111 Can I work on this?

[priyanka1111]

@SRvSaha you can take up this.

[SRvSaha]

Changes are done and PR raised.
PR #36
Please check @anilswm