fix(TetherContent): import isFunction from correct module

Author: ajmadsen

package.json

@@ -186,6 +186,7 @@
     "basic-math-utils": "^0.3.4",
     "bootstrap-styled": "^2.4.12",
     "classnames": "^2.2.6",
+    "lodash.isfunction": "^3.0.9",
     "lodash.omit": "^4.5.0",
     "map-to-css-modules": "^1.0.6",
     "prop-types": "^15.7.2",

src/TetherContent/index.js

@@ -6,7 +6,7 @@ import React from 'react';
 import PropTypes from 'prop-types';
 import ReactDOM from 'react-dom';
 import Tether from 'tether-fix';
-import isFunction from 'lodash.omit';
+import isFunction from 'lodash.isfunction';
 
 export const defaultProps = {
   isOpen: false,