package/ci: save *minutes* by not updating Homebrew.

Fingers crossed.

package/ci/travis.yml

@@ -182,11 +182,11 @@ install:
 - if [ "$TARGET" == "desktop" ] || [ "$TARGET" == "desktop-sanitizers" ] || [ "$TARGET" == "desktop-gles" ]; then printf "[General]\ndrivers=null" > ~/.alsoftrc; fi
 
 # SDL on macOS and iOS (cached)
-- if [ "$TRAVIS_OS_NAME" == "osx" ] && [ "$TARGET" == "desktop" ]; then brew install sdl2; fi
+- if [ "$TRAVIS_OS_NAME" == "osx" ] && [ "$TARGET" == "desktop" ]; then HOMEBREW_NO_AUTO_UPDATE=1 brew install sdl2; fi
 - if [ "$TRAVIS_OS_NAME" == "osx" ] && [ "$TARGET" == "ios-simulator" ]; then curl -O https://www.libsdl.org/release/SDL2-2.0.4.tar.gz && tar -xzvf SDL2-2.0.4.tar.gz && cd SDL2-2.0.4/Xcode-iOS/SDL && xcodebuild -sdk iphonesimulator9.3 | xcpretty && mkdir -p ../../../sdl2/lib && cp build/Release-iphonesimulator/libSDL2.a ../../../sdl2/lib && mkdir -p ../../../sdl2/include/SDL2 && cp -R ../../include/* ../../../sdl2/include/SDL2 && cd ../../..; fi
 
 # GLFW (cached)
-- if [ "$TRAVIS_OS_NAME" == "osx" ] && [ "$TARGET" == "desktop" ]; then brew install glfw; fi
+- if [ "$TRAVIS_OS_NAME" == "osx" ] && [ "$TARGET" == "desktop" ]; then HOMEBREW_NO_AUTO_UPDATE=1 brew install glfw; fi
 - if [ "$TRAVIS_OS_NAME" == "linux" ] && ( [ "$TARGET" == "desktop" ] || [ "$TARGET" == "desktop-sanitizers" ] ) && [ ! -e "$HOME/glfw/include" ]; then wget https://github.com/glfw/glfw/releases/download/3.1.2/glfw-3.1.2.zip && unzip glfw-3.1.2.zip && cd glfw-3.1.2 && mkdir build && cd build && cmake .. -DCMAKE_INSTALL_PREFIX=$HOME/glfw -DCMAKE_BUILD_TYPE=Release -DGLFW_BUILD_EXAMPLES=OFF -DGLFW_BUILD_TESTS=OFF -DGLFW_BUILD_DOCS=OFF -DBUILD_SHARED_LIBS=ON && cmake --build . --target install && cd ../..; fi
 
 script: