Revert to manual Homebrew commands, seems faster

.travis.yml

@@ -10,12 +10,6 @@ cache:
  - $HOME/Library/Caches/org.carthage.CarthageKit/dependencies
  - Carthage
 
-addons:
- homebrew:
- update: true
- packages:
- - carthage
-
 env:
  global:
  - LANG=en_US.UTF-8
@@ -37,7 +31,8 @@ env:
  - DESTINATION="platform=iOS Simulator,name=iPhone 8,OS=11.4" SCHEME="Telegraph iOS" RUN_TESTS="NO"
 
 before_install:
- # Install XCPretty
+ # Install Carthage and XCPretty
+ - brew outdated carthage || brew upgrade carthage
  - gem install xcpretty --no-rdoc --no-ri --no-document --quiet
 
 before_script: