install vyper in CI

.github/workflows/test.yml

@@ -57,7 +57,23 @@ jobs:
             npm install hardhat
             popd || exit
           fi
-
+      - name: Install Vyper
+        run: |
+          INSTALLDIR="$RUNNER_TEMP/vyper-install"
+          if [[ "$RUNNER_OS" = "Windows" ]]; then
+              URL="https://github.com/vyperlang/vyper/releases/download/v0.3.7/vyper.0.3.7+commit.6020b8bb.windows.exe"
+              FILENAME="vyper.exe"
+          elif [[ "$RUNNER_OS" = "Linux" ]]; then
+              URL="https://github.com/vyperlang/vyper/releases/download/v0.3.7/vyper.0.3.7+commit.6020b8bb.linux"
+              FILENAME="vyper"
+          else
+              echo "Unknown OS"
+              exit 1
+          fi
+          mkdir -p "$INSTALLDIR"
+          wget "$URL" -q -O "$INSTALLDIR/$FILENAME"
+          chmod 755 "$INSTALLDIR/$FILENAME"
+          echo "$INSTALLDIR" >> "$GITHUB_PATH"
       - name: Run ${{ matrix.type }} tests
         env:
           TEST_TYPE: ${{ matrix.type }}