Update supported Erlang versions to 19-23

.github/workflows/erlang.yml

@@ -11,11 +11,11 @@ jobs:
     strategy:
       matrix:
         otp: 
+          - 23
           - 22
           - 21
           - 20
           - 19
-          - 18
     steps:
       - uses: actions/checkout@v2
       - run: rebar3 compile

README.md

@@ -266,7 +266,7 @@ If you or your company use Meck and find it useful, [donations][liberapay] are g
 [hex]: https://hex.pm/packages/meck
 [hex version badge]: https://img.shields.io/hexpm/v/meck.svg?style=flat-square
 [hex license badge]: https://img.shields.io/hexpm/l/meck.svg?style=flat-square
-[erlang versions badge]: https://img.shields.io/badge/erlang-18--22-blue.svg?style=flat-square
+[erlang versions badge]: https://img.shields.io/badge/erlang-19--23-blue.svg?style=flat-square
 [erlang versions]: https://github.com/eproxus/meck/blob/master/.github/workflows/erlang.yml#L13-L18
 [build tool]: https://img.shields.io/badge/build%20tool-rebar3-orange.svg?style=flat-square
 [liberapay badge]: https://img.shields.io/liberapay/receives/eproxus.svg?logo=liberapay&style=flat-square