Run go test on github actions (#1047)

* Run go test on github actions

travis-ci.org has stopped.
See also: https://github.com/curl/curl/issues/7150

Downside: github actions don't support ppc64le

* Run less

* delete .travis.yml

* Remove travis + minor lint fixes

.github/workflows/security.yml

@@ -1,10 +1,14 @@
-on: [push, pull_request]
 name: Security
+on:
+  push:
+    branches:
+      - master
+  pull_request:
 jobs:
   test:
     strategy:
       matrix:
-        go-version: [1.13.x, 1.14.x, 1.15.x, 1.16.x]
+        go-version: [1.16.x]
         platform: [ubuntu-latest]
     runs-on: ${{ matrix.platform }}
     steps: