message: Change case in README
diff: @@ -68,7 +68,7 @@ Setup PHP with required extensions, php.ini configuration, code-coverage support
  |Windows Server 2019|`windows-latest` or `windows-2019`|
  |Ubuntu 18.04|`ubuntu-latest` or `ubuntu-18.04`|
  |Ubuntu 16.04|`ubuntu-16.04`|
  -|macOS X Catalina 10.15|`macos-latest` or `macOS-10.15`|
  +|macOS X Catalina 10.15|`macos-latest` or `macos-10.15`|
  ## :heavy_plus_sign: PHP Extension Support
  - On `ubuntu` by default extensions which are available as a package can be installed. PECL extensions if not available as a package can be installed by specifying `pecl` in the tools input.
  