Add cache action to tests (#104)

Also add 1.10-nightly

Author: caleb-allen

.github/workflows/test.yaml

@@ -14,7 +14,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        julia-version: ['1.7', '1.8', '1.9', '1.10']
+        julia-version: ['1.7', '1.8', '1.9', '1.10', '1.10-nightly']
         julia-arch: [x64]
         os: [ubuntu-latest, windows-latest, macOS-latest]
 
@@ -24,6 +24,7 @@ jobs:
         with:
           version: ${{ matrix.julia-version }}
           arch: ${{ matrix.julia-arch }}
+      - uses: julia-actions/cache@v2
       - uses: julia-actions/julia-buildpkg@v1
       - uses: julia-actions/julia-runtest@v1
         with: