Revert "Fail Travis CI build on compiler warnings"

This reverts commit f43c0fb.

It was eventually determined that failing the CI build on compiler warnings while compiling examples was too problematic due to the fact that warnings may be caused by external code.

Author: per1234

.travis.yml

@@ -2,7 +2,6 @@ language: generic
 env:
   global:
     - CLI_VERSION=latest
-    - EXTRA_COMPILER_WARNING_FLAGS="-Wpedantic -Werror"
 matrix:
   include:
     - env:
@@ -74,8 +73,8 @@ before_install:
   - installLibrary arduino-libraries/WiFi101
   - installLibrary arduino-libraries/WiFiNINA
   - installLibrary arduino-libraries/Ethernet
-  - buildExampleSketch() { arduino-cli compile --warnings all --build-properties compiler.c.extra_flags="${EXTRA_COMPILER_WARNING_FLAGS}" --build-properties compiler.cpp.extra_flags="${EXTRA_COMPILER_WARNING_FLAGS}" --build-properties compiler.S.extra_flags="${EXTRA_COMPILER_WARNING_FLAGS}" --fqbn $BOARD $PWD/examples/$1; }
-  - buildExampleUtilitySketch() { arduino-cli compile --warnings all --build-properties compiler.c.extra_flags="${EXTRA_COMPILER_WARNING_FLAGS}" --build-properties compiler.cpp.extra_flags="${EXTRA_COMPILER_WARNING_FLAGS}" --build-properties compiler.S.extra_flags="${EXTRA_COMPILER_WARNING_FLAGS}" --fqbn $BOARD $PWD/examples/utility/$1; }
+  - buildExampleSketch() { arduino-cli compile --warnings all --fqbn $BOARD $PWD/examples/$1; }
+  - buildExampleUtilitySketch() { arduino-cli compile --warnings all --fqbn $BOARD $PWD/examples/utility/$1; }
 install:
   - mkdir -p $HOME/Arduino/libraries
   - ln -s $PWD $HOME/Arduino/libraries/.