update readme; add ghactions

.github/workflows/ci.yml

@@ -0,0 +1,32 @@
+name: ssi-sdk-ci
+
+# when:
+#   - a pull request is opened against main
+#   - commits are pushed to main
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+  # used to run action manually via the UI
+  workflow_dispatch:
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: Set up Go
+      uses: actions/setup-go@v3
+      with:
+        go-version: 1.17
+
+    - name: Install mage
+      run: go install github.com/magefile/mage
+
+    - name: Build
+      run: mage build
+
+    - name: Test
+      run: mage test

README.md

@@ -3,6 +3,7 @@
 [![Go Report Card](https://goreportcard.com/badge/github.com/TBD54566975/ssi-sdk)](https://goreportcard.com/report/github.com/TBD54566975/ssi-sdk)
 [![license](https://img.shields.io/badge/license-Apache%202-black)](https://github.com/TBD54566975/ssi-sdk/blob/main/LICENSE)
 [![issues](https://img.shields.io/github/issues/TBD54566975/ssi-sdk)](https://github.com/TBD54566975/ssi-sdk/issues)
+![push](https://github.com/TBD54566975/ssi-sdk/workflows/ssi-sdk-ci/badge.svg?branch=main&event=push)
 
 # ssi-sdk
 
@@ -59,6 +60,22 @@ change as the library evolves.
 
 - [The did:key Method v0.7](https://w3c-ccg.github.io/did-method-key/) _Unofficial Draft 14 February 2022_
 
+# Building
+
+This project uses [mage](https://magefile.org/), please view [CONTRIBUTING](CONTRIBUTING.md) for more information.
+
+After installing mage, you can build and test the SDK with the following commands:
+```
+mage build
+mage test
+```
+
+A utility is provided to run _clean, build, and test_ in sequence with:
+
+```
+mage cbt
+```
+
 # Project Resources
 
 | Resource                              | Description                                                                   |