ci: Remove npm upgrade

Author: lpatino10

.travis.yml

@@ -8,7 +8,6 @@ before_install:
 - '[ "${TRAVIS_PULL_REQUEST}" = "false" ] && openssl aes-256-cbc -K $encrypted_320e4a7e27b3_key
   -iv $encrypted_320e4a7e27b3_iv -in auth.js.enc -out test/resources/auth.js -d ||
   true'
-- npm install npm@latest -g
 - npm install -g typescript
 script:
 - tsc