message: Update the README.md platform compatibility.
diff: @@ -37,7 +37,7 @@ For Ginkgo core library:
  * _cmake 3.9+_
  * C++11 compliant compiler, one of:
  - * _gcc 5.3+, 6.3+, 7.3+, 8.1+_
  + * _gcc 5.3+, 6.3+, 7.3+, 8.1+, 9.1+, 10.1+_
  * _clang 3.9+_
  * _Intel compiler 2017+_
  * _Apple LLVM 8.0+_ (__TODO__: verify)
  @@ -50,6 +50,7 @@ The Ginkgo CUDA module has the following __additional__ requirements:
  [CUDA installation guide for Linux](https://docs.nvidia.com/cuda/cuda-installation-guide-linux/index.html)
  or [CUDA installation guide for Mac Os X](https://docs.nvidia.com/cuda/cuda-installation-guide-mac-os-x/index.html)
  +
  In addition, if you want to contribute code to Ginkgo, you will also need the
  following:
  @@ -59,6 +60,7 @@ following:
  The Ginkgo HIP module has the following __additional__ requirements:
  +* _ROCm 2.8+_
  * the HIP, hipBLAS and hipSPARSE packages compiled with either:
  * _AMD_ backend
  * _CUDA 9.0+_ backend. When using CUDA 10+, _cmake 3.12.2+_ is required.
  @@ -68,8 +70,8 @@ The Ginkgo HIP module has the following __additional__ requirements:
  The prequirement needs to be verified
  * _cmake 3.9+_
  * C++11 compliant 64-bits compiler:
  - * _MinGW : gcc 5.3+, 6.3+, 7.3+, 8.1+_
  - * _Cygwin : gcc 5.3+, 6.3+, 7.3+, 8.1+_
  + * _MinGW : gcc 5.3+, 6.3+, 7.3+, 8.1+, 9.1+, 10.1+_
  + * _Cygwin : gcc 5.3+, 6.3+, 7.3+, 8.1+, 9.1+, 10.1+_
  * _Microsoft Visual Studio : VS 2017 15.7+_
  __NOTE:__ Need to add `--autocrlf=input` after `git clone` in _Cygwin_.
  