add ci for gcc 10, 11
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index ddf9ada..fdd25bf 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -21,6 +21,8 @@
           ubuntu-18.04-gcc-7,
           ubuntu-18.04-gcc-8,
           ubuntu-18.04-gcc-9,
+          ubuntu-20.04-gcc-10,
+          ubuntu-20.04-gcc-11,
           ubuntu-18.04-clang-3.8,
           ubuntu-18.04-clang-4.0,
           ubuntu-18.04-clang-5.0,
@@ -72,6 +74,16 @@
             compiler: gcc
             version: "9"
 
+          - name: ubuntu-20.04-gcc-10
+            os: ubuntu-20.04
+            compiler: gcc
+            version: "10"
+
+          - name: ubuntu-20.04-gcc-11
+            os: ubuntu-20.04
+            compiler: gcc
+            version: "11"
+
           - name: ubuntu-18.04-clang-3.8
             os: ubuntu-18.04
             compiler: clang
diff --git a/README.md b/README.md
index 4c55556..2dba30e 100644
--- a/README.md
+++ b/README.md
@@ -332,8 +332,8 @@
 
 Inja uses `string_view` from C++17, but includes the [polyfill](https://github.com/martinmoene/string-view-lite) from martinmoene. This way, the minimum version is C++11. Currently, the following compilers are tested:
 
-- GCC 4.8 - 9 (and possibly later)
-- Clang 3.5 - 9 (and possibly later)
+- GCC 5 - 11 (and possibly later)
+- Clang 3.8 - 11 (and possibly later)
 - Microsoft Visual C++ 2016 - 2019 (and possibly later)
 
 The unit tests fail to compile with GCC 4.8 but should just work fine. A complete list of supported compiler / os versions can be found in the [CI definition](https://github.com/pantor/inja/blob/master/.github/workflows/ci.yml).