Add warning bash function

* Allows displaying a warning, colored yellow, which is output to stderr

lib/bash-functions/warning.sh

@@ -0,0 +1,14 @@
+#!/bin/bash
+set -e
+set -o pipefail
+
+# Set up a handy repeatable warning output function that uses `stderr`
+#
+# @usage warning "Something may be wrong!"
+# @param $* Any information to pass into stderr
+function warning {
+  yellow='\033[33m'
+  clear='\033[0m'
+
+  echo -e "${yellow}[!] Warning: ${clear}$*" >&2
+}