Update .travis.yml

.travis.yml

@@ -30,6 +30,14 @@ addons: &gcc9
     sources:
       - ubuntu-toolchain-r-test
       
+# gcc 11.0
+addons: &gcc11
+  apt:
+    packages:
+      - g++-11
+    sources:
+      - ubuntu-toolchain-r-test
+
 
 # Clang 3.5
 addons: &clang35
@@ -79,6 +87,12 @@ matrix:
       os: linux
       addons: *gcc9
 
+    # Test gcc-11.0: C++20, Build=Debug
+    - env: GCC_VERSION=12 BUILD_TYPE=Debug CPP=20 ASAN=Off
+      os: linux
+      dist: bionic
+      addons: *gcc11
+      
     # Test clang-3.5: C++11, Build=Release
     - env: CLANG_VERSION=3.5 BUILD_TYPE=Release CPP=11
       os: linux
@@ -107,12 +121,6 @@ matrix:
       dist: bionic
       addons: *clang12
           
-    # Test clang-12.0: C++20, Build=Debug
-    - env: CLANG_VERSION=12 BUILD_TYPE=Debug CPP=20 ASAN=Off
-      os: linux
-      dist: bionic
-      addons: *clang12
-                        
                         
 before_script:
   - if [ -n "$GCC_VERSION" ]; then export CXX="g++-${GCC_VERSION}" CC="gcc-${GCC_VERSION}"; fi