chore(github): delete actions workflow

Sticking with TravisCI for now

.github/main.workflow

@@ -1,24 +0,0 @@
-workflow "Deploy demo app to Heroku" {
-  on = "push"
-  resolves = "release"
-}
-
-action "login" {
-  uses = "actions/heroku@master"
-  args = "container:login"
-  secrets = ["HEROKU_API_KEY"]
-}
-
-action "push" {
-  uses = "actions/heroku@master"
-  needs = "login"
-  args = "container:push -a karma-demo web"
-  secrets = ["HEROKU_API_KEY"]
-}
-
-action "release" {
-  uses = "actions/heroku@master"
-  needs = "push"
-  args = "container:release -a karma-demo web"
-  secrets = ["HEROKU_API_KEY"]
-}