Remove support for the deprecated config format

Author: gaearon

src/index.js

@@ -86,19 +86,6 @@ export default function ({ Plugin, types: t }) {
       Array.isArray(options.transforms);
   }
 
-  let didWarnAboutLegacyConfig = false;
-  function warnOnceAboutLegacyConfig() {
-    if (didWarnAboutLegacyConfig) {
-      return;
-    }
-    console.warn(
-      'Warning: you are using an outdated format of React Transform configuration. ' +
-      'Please update your configuration to the new format. See the Releases page for migration instructions: ' +
-      'https://github.com/gaearon/babel-plugin-react-transform/releases'
-    );
-    didWarnAboutLegacyConfig = true;
-  }
-
   /**
    * Enforces plugin options to be defined and returns them.
    */
@@ -108,15 +95,6 @@ export default function ({ Plugin, types: t }) {
     }
 
     let pluginOptions = file.opts.extra['react-transform'];
-    if (Array.isArray(pluginOptions)) {
-      warnOnceAboutLegacyConfig();
-      const transforms = pluginOptions.map(option => {
-        option.transform = option.transform || option.target;
-        return option;
-      });
-      pluginOptions = { transforms };
-    }
-
     if (!isValidOptions(pluginOptions)) {
       throw new Error(
         'babel-plugin-react-transform requires that you specify ' +