Use a different name depending on channel

This makes Atom beta install in %LOCALAPPDATA%\atom-beta and stable in 
%LOCALAPPDATA%\atom so that installs are side by side

script/config.js

@@ -27,11 +27,13 @@ const computedAppVersion = computeAppVersion(
 const channel = getChannel(computedAppVersion);
 const appName = getAppName(channel);
 const executableName = getExecutableName(channel, appName);
+const channelName = getChannelName(channel);
 
 module.exports = {
   appMetadata,
   apmMetadata,
   channel,
+  channelName,
   appName,
   executableName,
   computedAppVersion,
@@ -50,6 +52,12 @@ module.exports = {
   snapshotAuxiliaryData: {}
 };
 
+function getChannelName(channel) {
+  return channel === 'stable'
+    ? 'atom'
+    : `atom-${channel}`;
+}
+
 function getChannel(version) {
   const match = version.match(/\d+\.\d+\.\d+(-([a-z]+)(\d+|-\w{4,})?)?$/);
   if (!match) {

script/lib/create-windows-installer.js

@@ -12,6 +12,7 @@ module.exports = packagedAppPath => {
   const updateUrlPrefix =
     process.env.ATOM_UPDATE_URL_PREFIX || 'https://atom.io';
   const options = {
+    name: CONFIG.channelName,
     title: CONFIG.appName,
     exe: CONFIG.executableName,
     appDirectory: packagedAppPath,