fix(grunt): fix regex in grunt util to handle pre-release versions

NOTE: this also includes a temporary work-around for Bower

lib/grunt/utils.js

@@ -17,7 +17,9 @@ module.exports = {
     if (version) return version;
 
     var package = JSON.parse(fs.readFileSync('package.json', 'UTF-8'));
-    var match = package.version.match(/^([^\-]*)(-snapshot)?$/);
+    // TODO(brian): change `(-|rc)` to `-` in the regex below after bower
+    // fixes this issue: https://github.com/bower/bower/issues/782
+    var match = package.version.match(/^([^\-]*)(?:(-|rc)(.+))?$/);
     var semver = match[1].split('.');
     var hash = shell.exec('git rev-parse --short HEAD', {silent: true}).output.replace('\n', '');