Add dependabot for github actions, Updated dorny/test-reporter to version 2 and pinned the third party action (#57)

Author: enf0rc3

.github/dependabot.yml

@@ -0,0 +1,8 @@
+version: 2
+updates:
+
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      # Check for updates to GitHub Actions every week
+      interval: "weekly"

.github/workflows/main.yml

@@ -41,7 +41,7 @@ jobs:
         run: ./build.sh -target Test
 
       - name: Linux unit test report
-        uses: dorny/test-reporter@v1
+        uses: dorny/test-reporter@6e6a65b7a0bd2c9197df7d0ae36ac5cee784230c # v2.0.0
         if: success() || failure()    # run this step even if previous step failed
         with:
           name: Linux unit test results
@@ -77,7 +77,7 @@ jobs:
         run: ./build.ps1 --verbosity verbose
 
       - name: Windows unit test report
-        uses: dorny/test-reporter@v1
+        uses: dorny/test-reporter@6e6a65b7a0bd2c9197df7d0ae36ac5cee784230c # v2.0.0
         if: success() || failure()    # run this step even if previous step failed
         with:
           name: Windows unit test results