Clone library dependencies for CI build

There is a delay of hours before a library release becomes available for installation via Library Manager. For this reason, it's preferable to install library dependencies for the Travis CI build by cloning each library repository and checking out the newest Git tags.

Author: per1234

.travis.yml

@@ -52,15 +52,28 @@ before_install:
   - if [[ "$BOARD" =~ "arduino:samd:" ]]; then
       arduino-cli core install arduino:samd;
     fi
-  - arduino-cli lib install ArduinoCloudThing
-  - arduino-cli lib install ArduinoECCX08
-  - arduino-cli lib install ArduinoIoTCloudBearSSL
-  - arduino-cli lib install ArduinoMqttClient
-  - arduino-cli lib install MKRGSM
-  - arduino-cli lib install RTCZero
-  - arduino-cli lib install WiFi101
-  - arduino-cli lib install WiFiNINA
-  - arduino-cli lib install Ethernet
+  - |
+    installLibrary() {
+      local -r repositoryFullName="$1"
+      local -r repositoryName="${repositoryFullName##*/}"
+      # clone repository to the libraries folder of the sketchbook
+      git clone https://github.com/${repositoryFullName} "${HOME}/Arduino/libraries/${repositoryName}"
+      cd "${HOME}/Arduino/libraries/${repositoryName}"
+      # get new tags from the remote
+      git fetch --tags
+      # checkout the latest tag
+      git checkout $(git describe --tags `git rev-list --tags --max-count=1`)
+      cd "${TRAVIS_BUILD_DIR}"
+    }
+  - installLibrary arduino-libraries/ArduinoCloudThing
+  - installLibrary arduino-libraries/ArduinoECCX08
+  - installLibrary arduino-libraries/ArduinoIoTCloudBearSSL
+  - installLibrary arduino-libraries/ArduinoMqttClient
+  - installLibrary arduino-libraries/MKRGSM
+  - installLibrary arduino-libraries/RTCZero
+  - 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; }
 install: