README: Use GH Actions badge, drop Travis badge, configuration file (b…

…ootstrap-ruby#600)

* README: Use GH Actions badge, drop Travis badge

* Delete unused TravisCI configuration file

README.md

@@ -1,6 +1,6 @@
 # bootstrap_form
 
-[![Build Status](https://travis-ci.org/bootstrap-ruby/bootstrap_form.svg?branch=main)](https://travis-ci.org/bootstrap-ruby/bootstrap_form)
+[![Ruby](https://github.com/bootstrap-ruby/bootstrap_form/actions/workflows/ruby.yml/badge.svg)](https://github.com/bootstrap-ruby/bootstrap_form/actions/workflows/ruby.yml)
 [![Gem Version](https://badge.fury.io/rb/bootstrap_form.svg)](https://rubygems.org/gems/bootstrap_form)
 
 `bootstrap_form` is a Rails form builder that makes it super easy to integrate Bootstrap v5-style forms into your Rails application. It provides form helpers that augment the Rails form helpers. `bootstrap_forms`'s form helpers generate the form field and its label and all the Bootstrap mark-up required for proper Bootstrap display. `bootstrap_form` also provides: