Replace travis with github actions (#9641)

* Move outside of travis to Github actions

This will permit to have better integrated CI workflow than the previous
travis one.

util/ci/lint.sh

@@ -0,0 +1,43 @@
+#! /bin/bash
+function perform_lint() {
+	echo "Performing LINT..."
+	if [ -z "${CLANG_FORMAT}" ]; then
+		CLANG_FORMAT=clang-format
+	fi
+	echo "LINT: Using binary $CLANG_FORMAT"
+	CLANG_FORMAT_WHITELIST="util/ci/clang-format-whitelist.txt"
+
+	files_to_lint="$(find src/ -name '*.cpp' -or -name '*.h')"
+
+	local errorcount=0
+	local fail=0
+	for f in ${files_to_lint}; do
+		d=$(diff -u "$f" <(${CLANG_FORMAT} "$f") || true)
+
+		if ! [ -z "$d" ]; then
+			whitelisted=$(awk '$1 == "'$f'" { print 1 }' "$CLANG_FORMAT_WHITELIST")
+
+			# If file is not whitelisted, mark a failure
+			if [ -z "${whitelisted}" ]; then
+				errorcount=$((errorcount+1))
+
+				printf "The file %s is not compliant with the coding style" "$f"
+				if [ ${errorcount} -gt 50 ]; then
+					printf "\nToo many errors encountered previously, this diff is hidden.\n"
+				else
+					printf ":\n%s\n" "$d"
+				fi
+
+				fail=1
+			fi
+		fi
+	done
+
+	if [ "$fail" = 1 ]; then
+		echo "LINT reports failure."
+		exit 1
+	fi
+
+	echo "LINT OK"
+}
+