#18 Copy warning module into src

src/Reduxible.js

@@ -5,7 +5,7 @@ import createBrowserHistory from 'history/lib/createBrowserHistory';
 import createHashHistory from 'history/lib/createHashHistory';
 import createMemoryHistory from 'history/lib/createMemoryHistory';
 import contextMiddleware from './contextMiddlerware';
-import warning from 'redux/lib/utils/warning';
+import warning from './warning';
 
 export default class Reduxible {
   constructor(options = {}) {

src/warning.js

@@ -0,0 +1,13 @@
+/**
+ * Prints a warning in the console if it exists.
+ *
+ * @param {String} message The warning message.
+ * @returns {void}
+ */
+export default function warning(message) {
+  /* eslint-disable no-console */
+  if (typeof console !== 'undefined' && typeof console.error === 'function') {
+    console.error(message);
+  }
+  /* eslint-enable no-console */
+}