code: function getInstalledPhoneSdks () {
      var installedSdks = [];
      return spawn('reg', ['query', 'HKLM\\SOFTWARE\\Microsoft\\Microsoft SDKs\\Windows Phone\\v8.1', '/v', 'InstallationFolder', '/reg:32'])
          .fail(function () { return ''; })
          .then(function (output) {
              var match = /\\Microsoft SDKs\\Windows Phone\\v(\d+\.\d+)\s*InstallationFolder\s+REG_SZ\s+(.*)/gim.exec(output);
              if (match && shell.test('-e', path.join(match[2], 'SDKManifest.xml'))) {
                  installedSdks.push(Version.tryParse(match[1]));
              }
          }).then(function () {
              return spawn('reg', ['query', 'HKLM\\SOFTWARE\\Microsoft\\Microsoft SDKs\\Windows\\v10.0', '/v', 'InstallationFolder', '/reg:32']);
          }).fail(function () {
              return '';
          }).then(function (output) {
              var match = /\\Microsoft SDKs\\Windows\\v(\d+\.\d+)\s*InstallationFolder\s+REG_SZ\s+(.*)/gim.exec(output);
              if (match && shell.test('-e', path.join(match[2], 'SDKManifest.xml'))) {
                  installedSdks.push(Version.tryParse(match[1]));
              }
          }).thenResolve(installedSdks);
  }
docs: Gets list of installed Windows Phone SDKs. Separately searches for 8.1 Phone
  SDK and Windows 10 SDK, because the latter is needed for both Windows and
  Windows Phone applications.
  
  @return  {Version[]}  List of installed Phone SDKs' versions.