Fix travis file: remove deprecated options to install xcpretty

Author: e-marchand

.travis.yml

@@ -13,7 +13,7 @@ env:
     - DESTINATION="OS=12.2,name=iPhone 8" SCHEME="$IOS_FRAMEWORK_SCHEME" SDK="$IOS_SDK" RUN_TESTS="NO"
     - DESTINATION="arch=x86_64" SCHEME="$MACOS_FRAMEWORK_SCHEME" SDK="$MACOS_SDK" RUN_TESTS="NO"
 before_install:
-  - gem install xcpretty --no-rdoc --no-ri --no-document --quiet
+  - gem install xcpretty --no-document --quiet
 script:
   - set -o pipefail
   - xcodebuild -version