Check for commonly misspelled words during Travis CI build

Author: per1234

.travis.yml

@@ -60,6 +60,11 @@ before_install:
   # Check for files that don't end in a newline (https://stackoverflow.com/a/25686825)
   - find . -path ./.git -prune -o -type f -print0 | xargs -0 -L1 bash -c 'if test "$(grep --files-with-matches --binary-files=without-match --max-count=1 --regexp='.*' "$0")" && test "$(tail --bytes=1 "$0")"; then echo "No new line at end of $0."; false; fi'
 
+  # Check for typos
+  - git clone https://github.com/ss18/grep-typos.git "${HOME}/scripts/grep-typos"
+  - find "$TRAVIS_BUILD_DIR" -path "${TRAVIS_BUILD_DIR}/.git" -prune -or -type f -print0 | xargs --null --max-args=1 bash "${HOME}/scripts/grep-typos/grep_typos.sh" "$0"
+  - rm "${HOME}/scripts/grep-typos" --recursive --force
+
   - source "${TRAVIS_BUILD_DIR}/arduino-ci-script.sh"
 
   - set_script_verbosity "$VERBOSITY_LEVEL"