add missing unit test

Unfortunately, I made a mistake in 35c0a41

Author: johnnychen94

.github/workflows/UnitTest.yml

@@ -37,6 +37,9 @@ jobs:
             ${{ runner.os }}-test-${{ env.cache-name }}-
             ${{ runner.os }}-test-
             ${{ runner.os }}-
+            
+      - name: "Unit Test"
+        uses: julia-actions/julia-runtest@master
 
       - uses: julia-actions/julia-processcoverage@v1
       - uses: codecov/codecov-action@v1