Merge pull request #14 from yisoft-dotnet/dev

 fix Microsoft.Extensions.Configuration.Abstractions version.

Merge pull request #12 from yisoft-dotnet/dev

bumped version to 2.2.0

Merge pull request #10 from yisoft-dotnet/dev

update to netstandard 2.0

Merge pull request #8 from yisoft-dotnet/dev

update versions

Merge pull request #6 from yisoft-dotnet/dev

add more string manipulation methods

Merge pull request #4 from yisoft-dotnet/dev

merge from dev

Merge pull request #2 from yisoft/dev

code initial