Make tests more reliable avoiding false positives (#33)

* Make tests more reliable avoiding false positives

* Restart cable server (and unsubscribe on redis) before each test

* two more sleeps and we are done

* Update src/cable/server.cr

remove unused variable

Co-authored-by: Jeremy Woertink <jeremywoertink@gmail.com>

Co-authored-by: Jeremy Woertink <jeremywoertink@gmail.com>

.github/workflows/ci.yml

@@ -18,6 +18,7 @@ jobs:
         crystal_version:
           - 0.36.1
           - 1.0.0
+          - 1.1.1
     runs-on: ubuntu-latest
     container: crystallang/crystal:${{ matrix.crystal_version }}-alpine
     services:

README.md

@@ -1,6 +1,6 @@
 # Cable
 
-![ci workflow](https://github.com/cable-cr/cable/actions/workflows/ci.yml/badge.svg)
+[![ci workflow](https://github.com/cable-cr/cable/actions/workflows/ci.yml/badge.svg)](https://github.com/cable-cr/cable/actions/workflows/ci.yml)
 
 It's like [ActionCable](https://guides.rubyonrails.org/action_cable_overview.html) (100% compatible with JS Client), but you know, for Crystal