OSX Image to 8.3, update README.md

.travis.yml

@@ -9,7 +9,7 @@ dotnet: 2.0.3
 os:
   - linux
   - osx
-osx_image: xcode8.2
+osx_image: xcode8.3
 branches:
   only:
     - master

README.md

@@ -18,14 +18,14 @@ All new development is done on the dev branch. More stable versions of the packa
 
 [Master feed (Stable)](https://www.myget.org/gallery/steeltoemaster) - https://www.myget.org/gallery/steeltoemaster
 
-[Release or Release Candidate feed](https://www.nuget.org/) - https://www.nuget.org/. 
+[Release or Release Candidate feed](https://www.nuget.org/) - https://www.nuget.org/
 
 ## Building Pre-requisites
 
 To build and run the unit tests:
 
-1. .NET Core SDK 2.0.0 or greater
-1. .NET Core Runtime 2.0
+1. .NET Core SDK 2.0.3 or greater
+1. .NET Core Runtime 2.0.3
 
 ## Building Packages & Running Tests - Windows
 
@@ -59,7 +59,7 @@ To build the packages on Linux/OSX:
 
 The resulting artifacts can be found in the bin folder under the corresponding project. (e.g. src/Steeltoe.Common/bin
 
-To run the unit tests: 
+To run the unit tests
 
 1. git clone ...
 1. cd `<clone directory>`