WIP: Start preparing release v3.0.7 (#147)

* Use ooni/probe-engine 0.16.0
* Update all the other dependencies
* Use GitHub Actions rather than Travis CI
* Automatically build and test binaries on the target OS (for Windows, macOS, Linux on amd64)
* Make sure we correctly measure coverage
* Make sure we use `-race` when running tests
* Remove unnecessary scripts
* Make sure the README is up-to-date
* Write small script to update binary data and add GitHub Actions checks for it
* Notice that we needed to run ./updatebindata.sh and run it
* Self documenting instructions regarding cross compiling
* Set version number to v3.0.7-beta

Part of https://github.com/ooni/probe-engine/issues/748

.github/workflows/bindata.yml

@@ -0,0 +1,22 @@
+# Make sure we can embed bindata
+name: bindata
+on:
+  push:
+  schedule:
+    - cron: "14 17 * * 3"
+jobs:
+  test:
+    runs-on: "${{ matrix.os }}"
+    strategy:
+      fail-fast: false
+      matrix:
+        os: ["ubuntu-latest"]
+        go: ["1.14"]
+    steps:
+      - uses: actions/setup-go@v1
+        with:
+          go-version: ${{ matrix.go }}
+      - uses: actions/checkout@v2
+      - run: ./updatebindata.sh
+      - run: go mod tidy  # revert changes caused by installing bindata
+      - run: git diff --exit-code  # if this fails, run ./updatebindata.sh locally and push