Don't fallback to default mapping when property is ignored

Resolves henkmollema#81

Bump package versions

Merge pull request henkmollema#60 from henkmollema/sdk-2.0

Update to .NET Core SDK 2.0

Update to .NET Core RTM (henkmollema#40)

* Update to .NET Core RTM

- .NETStandard Library v1.6.0
- Dapper v1.50.0
- xUnit 2.2.0-* builds
- KoreBuild v1.0.0

* Fix OS X build

* Throw when adding entity map fails

* Update Dommel extension to .NET Core RTM

- Dapper.FluentMap v1.5.1
- Dommel v1.6.1

Migrate to .NETStandard (henkmollema#39)

* Migrate to .NETStandard 1.3
* Fix Linux/OSX build
* Make type conventions dictionary concurrent
* Fix license version, remove unused files
* Fix package metadata
* Add comments

Update README.md

Deploy Dapper.FluentMap.Dommel v1.2.1

Update repositories.config