Simplify CI

Author: ChrisRackauckas

.github/workflows/ci.yml

@@ -9,9 +9,7 @@ on:
 jobs:
   test:
     runs-on: ubuntu-latest
-    continue-on-error: ${{ matrix.group == 'Downstream' }}
     strategy:
-      fail-fast: false
       matrix:
         group:
           - Core
@@ -33,10 +31,11 @@ jobs:
             ${{ runner.os }}-test-${{ env.cache-name }}-
             ${{ runner.os }}-test-
             ${{ runner.os }}-
-      - run: julia .ci/test.jl
+      - uses: julia-actions/julia-buildpkg@v1
+      - uses: julia-actions/julia-runtest@v1
         env:
           GROUP: ${{ matrix.group }}
       - uses: julia-actions/julia-processcoverage@v1
       - uses: codecov/codecov-action@v1
         with:
-          file: lcov.info
+          file: lcov.info