Add GHA

.github/workflows/main.yml

@@ -0,0 +1,19 @@
+name: Test
+on: [push, pull_request]
+jobs:
+  test:
+    # matrix strategy from: https://github.com/mvdan/github-actions-golang/blob/master/.github/workflows/test.yml
+    strategy:
+      matrix:
+        go-version: [1.13.x, 1.14.x]
+        platform: [ubuntu-latest]
+    runs-on: ${{ matrix.platform }}
+    steps:
+    - name: Install Go
+      uses: actions/setup-go@v1
+      with:
+        go-version: ${{ matrix.go-version }}
+    - name: Checkout code
+      uses: actions/checkout@v2
+    - name: Run tests
+      run: go test

README.md

@@ -1,4 +1,4 @@
-# go-merkletree [![Go Report Card](https://goreportcard.com/badge/github.com/iden3/go-merkletree)](https://goreportcard.com/report/github.com/iden3/go-merkletree)
+# go-merkletree [![GoDoc](https://godoc.org/github.com/iden3/go-merkletree?status.svg)](https://godoc.org/github.com/iden3/go-merkletree) [![Go Report Card](https://goreportcard.com/badge/github.com/iden3/go-merkletree)](https://goreportcard.com/report/github.com/iden3/go-merkletree) [![Test](https://github.com/iden3/go-merkletree/workflows/Test/badge.svg)](https://github.com/iden3/go-merkletree/actions?query=workflow%3ATest)
 
 MerkleTree compatible with version from [circomlib](https://github.com/iden3/circomlib).