new: push develop/master branch docker images (#80)

* new: push develop/master branch docker images

* fix: typo !minor

.github/workflows/dockerimage-latest.yml

+name: Docker Images For Latest Branches
+
+on:
+  push:
+    branches:
+      - develop
+      - master
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: Build docker image
+      env:
+        DOCKERHUB: ${{ secrets.DOCKERHUB }}
+        DOCKERHUB_KEY: ${{ secrets.DOCKERHUB_KEY }}
+      run: |
+        ls -l
+        echo "Docker login"
+        docker login -u $DOCKERHUB -p $DOCKERHUB_KEY
+        echo "Running build"
+        docker build -t maticnetwork/bor:${GITHUB_REF/refs\/heads\//} .
+        echo "Pushing image"
+        docker push maticnetwork/bor:${GITHUB_REF/refs\/heads\//}
+        echo "Done"