build system: updated GH workflow

.github/workflows/build.yml

@@ -12,12 +12,12 @@ jobs:
       matrix:
         compiler: [
             g++-7, g++-8, g++-9, g++,
-            clang++-8, clang++-9, clang++
+            clang++-8, clang++-9, clang++-10, clang++
         ]
         mode: [-DBUILD_UVW_SHARED_LIB=ON, -DBUILD_UVW_LIBS=ON, -DBUILD_UVW_LIBS=OFF]
 
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
     - name: Install g++-7
       if: ${{ matrix.compiler == 'g++-7' }}
       run: |
@@ -33,6 +33,16 @@ jobs:
       run: |
         sudo apt-get update
         sudo apt-get install clang-8 -y
+    - name: Install clang-9
+      if: ${{ matrix.compiler == 'clang++-9' }}
+      run: |
+        sudo apt-get update
+        sudo apt-get install clang-9 -y
+    - name: Install clang-10
+      if: ${{ matrix.compiler == 'clang++-10' }}
+      run: |
+        sudo apt-get update
+        sudo apt-get install clang-10 -y
     - name: Compile tests
       working-directory: build
       env: