ci: add ci steps for running benchmark tests

Added third party gh-action for A/B testing
of performance degradation.

Follows up #122

Author: vr009

.github/workflows/testing.yml

@@ -44,3 +44,23 @@ jobs:
 
       - name: Run tests
         run: make test
+
+      - name: Run becnchmark
+        run: |
+          make bench
+
+      - uses: WillAbides/benchdiff-action@v0
+        with:
+          benchdiff_version: 0.6.2
+          status_name: test-bench-result
+          status_on_degraded: neutral
+          benchdiff_args: |
+            --bench="."
+            --count=10
+            --warmup-count=1
+            --benchtime=500ms
+            --debug
+            --benchstat-output=markdown
+            --tolerance=50
+            --clear-cache
+            --base-ref=origin/master