chore: remove travis

Replaced by github actions: test.
Plus it's dumb.

.travis.yml

@@ -1,21 +0,0 @@
-language: node_js
-
-node_js: lts/*
-
-services:
-  - redis-server
-
-install:
-  - yarn
-
-script:
-  - npm run test
-
-after_script:
-  - npm install codecov
-  - ./node_modules/.bin/codecov
-
-cache:
-  yarn: true
-  directories:
-    - node_modules