Try to have a better travis

.travis.yml

@@ -8,22 +8,18 @@ compiler: gcc
 matrix:
   include:
     - os: osx
-      osx_image: xcode9.2   # OS X 10.13
+      osx_image: xcode11
     - os: linux
       dist: xenial
       sudo: required
 
-before_install:
-## Install ARM toolchain on Linux.
-## add our homebrew tap for MacOS
-## Note: all dependencies on MacOS should be resolved by the brew install command
-  if [[ "$TRAVIS_OS_NAME" == "linux" ]]; then 
-    sudo apt-get update -qq;
-    sudo apt-get install -y gcc-arm-none-eabi libnewlib-dev;
-  elif [[ "$TRAVIS_OS_NAME" == "osx" ]]; then
-    brew update;
-    brew tap RfidResearchGroup/proxmark3;
-  fi
+addons:
+  apt:
+    packages:
+      - gcc-arm-none-eabi
+      - libnewlib-dev
+  homebrew:
+    taps: RfidResearchGroup/proxmark3
 
 install:
   if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then 
@@ -34,8 +30,6 @@ install:
     make all;
   fi
 
-before_script:
-
 script: 
 ## start and run a test script
   if [[ "$TRAVIS_OS_NAME" == "osx" ]]; then