Build: Don't run tests on grunt

Running `grunt` will now just build Sizzle, do a size comparison & run ESLint,
similarly to what we do in jQuery. `grunt test` is used to run unit tests and
it requires running `grunt` or `grunt build` before to generate the built Sizzle
version.

Gruntfile.js

@@ -277,7 +277,6 @@ module.exports = function( grunt ) {
 	] );
 	grunt.registerTask( "default", [
 		"build",
-		"tests",
 		"compare_size",
 		"eslint:dist"
 	] );

build/release.js

@@ -13,7 +13,7 @@ module.exports = function( Release ) {
 		issueTracker: "github",
 
 		generateArtifacts: function( done ) {
-			Release.exec( "grunt build", "Grunt command failed" );
+			Release.exec( "grunt", "Grunt command failed" );
 			done( files );
 		}
 	} );

package.json

@@ -66,7 +66,7 @@
   "scripts": {
     "build": "npm install && grunt",
     "start": "grunt start",
-    "test": "grunt test"
+    "test": "grunt && grunt test"
   },
   "commitplease": {
     "components": [