convert test/unit/grep.spec.js to unexpected

Signed-off-by: Christopher Hiller <boneskull@boneskull.com>

test/unit/grep.spec.js

@@ -6,19 +6,19 @@ describe('Mocha', function () {
   describe('"grep" option', function () {
     it('should add a RegExp to the mocha.options object', function () {
       var mocha = new Mocha({ grep: /foo.*/ });
-      expect(mocha.options.grep.toString()).to.equal('/foo.*/');
+      expect(mocha.options.grep, 'to equal', /foo.*/);
     });
 
     it('should convert string to a RegExp', function () {
       var mocha = new Mocha({ grep: 'foo.*' });
-      expect(mocha.options.grep.toString()).to.equal('/foo.*/');
+      expect(mocha.options.grep, 'to equal', /foo.*/);
     });
   });
 
   describe('"fgrep" option', function () {
     it('should escape and convert string to a RegExp', function () {
       var mocha = new Mocha({ fgrep: 'foo.*' });
-      expect(mocha.options.grep.toString()).to.equal('/foo\\.\\*/');
+      expect(mocha.options.grep, 'to equal', /foo\.\*/);
     });
   });
 
@@ -27,7 +27,7 @@ describe('Mocha', function () {
     function testGrep (mocha) {
       return function testGrep (grep, expected) {
         mocha.grep(grep);
-        expect(mocha.options.grep.toString()).to.equal(expected);
+        expect(String(mocha.options.grep), 'to be', expected);
       };
     }
 
@@ -52,9 +52,9 @@ describe('Mocha', function () {
       test('/^foo(.*)bar/g', '/^foo(.*)bar/g');
     });
 
-    it('should return it\'s parent Mocha object for chainability', function () {
+    it('should return its parent Mocha object for chainability', function () {
       var mocha = new Mocha();
-      expect(mocha.grep()).to.equal(mocha);
+      expect(mocha.grep(), 'to be', mocha);
     });
   });