Remove code formatting CI check

Unfortunately, this turned out to be too ambitious of an initiative for Arduino.
See arduino-libraries/Arduino_MKRGPS PR# 1 for details.

Author: per1234

.travis.yml

@@ -28,26 +28,6 @@ matrix:
       install:
         - arduino-cli core install arduino:sam
 
-    # check all code files for compliance with the Arduino code formatting style
-    - env:
-        - NAME='Code Formatting Check'
-      language: minimal
-      before_install:
-        # install Artistic Style code formatter tool: http://astyle.sourceforge.net
-        - |
-          mkdir "${HOME}/astyle";
-          wget --no-verbose --output-document="${HOME}/astyle/astyle.tar.gz" "https://iweb.dl.sourceforge.net/project/astyle/astyle/astyle%203.1/astyle_3.1_linux.tar.gz";
-          tar --extract --file="${HOME}/astyle/astyle.tar.gz" --directory="${HOME}/astyle";
-          cd "${HOME}/astyle/astyle/build/gcc";
-          make;
-          export PATH="$PWD/bin:$PATH";
-          cd "$TRAVIS_BUILD_DIR"
-        # download Arduino's Artistic Style configuration file
-        - wget --directory-prefix="${HOME}/astyle" https://raw.githubusercontent.com/arduino/Arduino/master/build/shared/examples_formatter.conf
-      script:
-        # check code formatting
-        - find . -regextype posix-extended -path './.git' -prune -or \( -iregex '.*\.((ino)|(h)|(hpp)|(hh)|(hxx)|(h\+\+)|(cpp)|(cc)|(cxx)|(c\+\+)|(cp)|(c)|(ipp)|(ii)|(ixx)|(inl)|(tpp)|(txx)|(tpl))$' -and -type f \) -print0 | xargs -0 -L1 bash -c 'if ! diff "$0" <(astyle --options=${HOME}/astyle/examples_formatter.conf --dry-run < "$0"); then echo "Non-compliant code formatting in $0"; false; fi'
-
     # check all files for commonly misspelled words
     - env:
         - NAME='Spell Check'