Update ci.yml

Author: pdimov

.github/workflows/ci.yml

@@ -19,18 +19,18 @@ jobs:
         include:
           - toolset: gcc-4.8
             cxxstd: "03,11"
-            os: ubuntu-latest
             container: ubuntu:18.04
+            os: ubuntu-latest
             install: g++-4.8
           - toolset: gcc-5
             cxxstd: "03,11,14,1z"
-            os: ubuntu-latest
             container: ubuntu:18.04
+            os: ubuntu-latest
             install: g++-5
           - toolset: gcc-6
             cxxstd: "03,11,14,1z"
-            os: ubuntu-latest
             container: ubuntu:18.04
+            os: ubuntu-latest
             install: g++-6
           - toolset: gcc-7
             cxxstd: "03,11,14,17"
@@ -68,20 +68,20 @@ jobs:
           - toolset: clang
             compiler: clang++-3.9
             cxxstd: "03,11,14"
-            os: ubuntu-latest
             container: ubuntu:18.04
+            os: ubuntu-latest
             install: clang-3.9
           - toolset: clang
             compiler: clang++-4.0
             cxxstd: "03,11,14"
-            os: ubuntu-latest
             container: ubuntu:18.04
+            os: ubuntu-latest
             install: clang-4.0
           - toolset: clang
             compiler: clang++-5.0
             cxxstd: "03,11,14,1z"
-            os: ubuntu-latest
             container: ubuntu:18.04
+            os: ubuntu-latest
             install: clang-5.0
           - toolset: clang
             compiler: clang++-6.0