removing apt-get lines from travis config

.travis.yml

@@ -1,8 +1,6 @@
 services:
   - redis-server
 before_install:
- - sudo apt-get update -qq
- - sudo apt-get install -qq redis-server imagemagick
  - npm i --production
  - node app --setup="{\"base_url\":\"http://127.0.0.1\",\"port\":4567,\"use_port\":false,\"secret\":\"abcdef\",\"bind_address\":\"0.0.0.0\",\"database\":\"redis\",\"redis:host\":\"127.0.0.1\",\"redis:port\":6379,\"redis:password\":\"\",\"redis:database\":0,\"admin:username\":\"admin\",\"admin:email\":\"test@example.org\",\"admin:password\":\"abcdef\",\"admin:password:confirm\":\"abcdef\"}"
 language: node_js