Update README.md

Author: SimonDanisch

README.md

@@ -151,15 +151,15 @@ Times in a table:
 
 # Installation
 
-Recently I added a lot of features and bug fixes to the master branch.
+I recently added a lot of features and bug fixes to the master branch.
 Please check that out first and see [pull #37](https://github.com/JuliaGPU/GPUArrays.jl/pull/37) for a list of new features.
 
-For the cudanative backend, you need to install [CUDAnative.jl manually](https://github.com/JuliaGPU/CUDAnative.jl/#installation).
-The cudanative backend only works on 0.6, while the other backends also support Julia 0.5.
-Make sure to have CUDA and OpenCL driver installed correctly.
+For the cudanative backend, you need to install [CUDAnative.jl manually](https://github.com/JuliaGPU/CUDAnative.jl/#installation) and it works only on osx + linux with a julia source build.
+Make sure to have either CUDA and/or OpenCL drivers installed correctly.
 `Pkg.build("GPUArrays")` will pick those up and should include the working backends.
 So if your system configuration changes, make sure to run `Pkg.build("GPUArrays")` again.
 The rest should work automatically:
+
 ```Julia
 Pkg.add("GPUArrays")
 Pkg.build("GPUArrays") # should print out information about what backends are added