added devel package in README.md

fixed Core.Test codecov report error

Author: Aragas

README.md

@@ -1,6 +1,6 @@
-**Mono & .NET Core:** | **.NET 4.5 & .NET Core:** | **NuGet** | **Coveralls** | **Codecov**
------------- | ------------- | ------------- | ------------- | -------------
- | [![Build Status](https://travis-ci.org/PCLExt/PCLExt.FileStorage.svg?branch=master)](https://travis-ci.org/PCLExt/PCLExt.FileStorage) | [![Build status](https://ci.appveyor.com/api/projects/status/puku2ym0k1n7ryde?svg=true)](https://ci.appveyor.com/project/Aragas/pclext-filestorage) [![AppVeyor tests](https://img.shields.io/appveyor/tests/Aragas/pclext-filestorage.svg)]() | [![NuGet](https://img.shields.io/nuget/v/PCLExt.FileStorage.svg)](https://www.nuget.org/packages/PCLExt.FileStorage/) | [![Coverage Status](https://coveralls.io/repos/github/PCLExt/PCLExt.FileStorage/badge.svg?branch=master)](https://coveralls.io/github/PCLExt/PCLExt.FileStorage?branch=master) | [![codecov](https://codecov.io/gh/PCLExt/PCLExt.FileStorage/branch/master/graph/badge.svg)](https://codecov.io/gh/PCLExt/PCLExt.FileStorage)
+**Mono & .NET Core:** | **.NET 4.5 & .NET Core:** | **NuGet** |**NuGet devel** | **Coveralls** | **Codecov**
+------------ | ------------- | ------------- | ------------- | ------------- | -------------
+ | [![Build Status](https://travis-ci.org/PCLExt/PCLExt.FileStorage.svg?branch=master)](https://travis-ci.org/PCLExt/PCLExt.FileStorage) | [![Build status](https://ci.appveyor.com/api/projects/status/puku2ym0k1n7ryde?svg=true)](https://ci.appveyor.com/project/Aragas/pclext-filestorage) [![AppVeyor tests](https://img.shields.io/appveyor/tests/Aragas/pclext-filestorage.svg)]() | [![NuGet](https://img.shields.io/nuget/v/PCLExt.FileStorage.svg)](https://www.nuget.org/packages/PCLExt.FileStorage/) | [![NuGet devel](https://img.shields.io/nuget/v/PCLExt.FileStorage-devel.svg)](https://www.nuget.org/packages/PCLExt.FileStorage-devel/) | [![Coverage Status](https://coveralls.io/repos/github/PCLExt/PCLExt.FileStorage/badge.svg?branch=master)](https://coveralls.io/github/PCLExt/PCLExt.FileStorage?branch=master) | [![codecov](https://codecov.io/gh/PCLExt/PCLExt.FileStorage/branch/master/graph/badge.svg)](https://codecov.io/gh/PCLExt/PCLExt.FileStorage)
 
 # PCLExt.FileStorage
 

after_test_fx_core.ps1

@@ -6,7 +6,7 @@ CD test\PCLExt.FileStorage.Core.Test
 dotnet add package coverlet.msbuild
 dotnet test /p:CollectCoverage=true /p:CoverletOutputFormat=opencover /p:Exclude=[NUnit*]*
 csmacnz.coveralls --opencover -i coverage.opencover.xml --repoToken $env:COVERALLS_REPO_TOKEN
-codecov -f coverage_netfx.xml
+codecov -f coverage.opencover.xml
 
 # PCLExt.FileStorage.NetFX.Test
 CD $env:APPVEYOR_BUILD_FOLDER