skip verification for prereleases because we remove it from release.json

src/updater.js

@@ -22,6 +22,7 @@ var assert = require('assert'),
     paths = require('./paths.js'),
     progress = require('./progress.js'),
     safe = require('safetydance'),
+    semver = require('semver'),
     shell = require('./shell.js'),
     updateChecker = require('./updatechecker.js'),
     util = require('util'),
@@ -122,6 +123,9 @@ function verifyUpdateInfo(versionsFile, updateInfo, callback) {
     assert.strictEqual(typeof updateInfo, 'object');
     assert.strictEqual(typeof callback, 'function');
 
+    // skip verification for prereleases because we remove it from release.json
+    if (semver.prerelease(config.version()) !== null) return callback();
+
     var releases = safe.JSON.parse(safe.fs.readFileSync(versionsFile, 'utf8')) || { };
     if (!releases[config.version()] || !releases[config.version()].next) return callback(new UpdaterError(UpdaterError.EXTERNAL_ERROR, 'No version info'));
     var nextVersion = releases[config.version()].next;