Rename file and fix require path

Author: kgryte

lib/node_modules/@stdlib/math/base/tools/evalrational/test/test.evalrational.js renamed to lib/node_modules/@stdlib/math/base/tools/evalrational/test/test.main.js

@@ -22,7 +22,7 @@
 
 var tape = require( 'tape' );
 var isnan = require( '@stdlib/math/base/assert/is-nan' );
-var evalrational = require( './../lib/evalrational.js' );
+var evalrational = require( './../lib/main.js' );
 
 
 // TESTS //