add ciCompare for comparing two strings ignoring their case

lib/string.js

@@ -2,5 +2,6 @@
 
 module.exports = {
     append: (str, append) => str + append,
-    toBool: val => val === 'true'
+    toBool: val => val === 'true',
+    ciCompare: (val1 = '', val2 = '') => val1.toLowerCase() === val2.toLowerCase()
 };

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@mightyplow/jslib",
-  "version": "0.6.1",
+  "version": "0.7.0",
   "description": "js, helpers library",
   "main": "jslib.js",
   "devDependencies": {