message: Use openReadOnlyContent for deployment logs
diff: import { SiteSourceControl } from 'azure-arm-website/lib/models';
  import * as os from 'os';
  -import { ProgressLocation, TextDocument, window, workspace } from 'vscode';
  -import { AzureTreeItem, TreeItemIconPath } from 'vscode-azureextensionui';
  +import { ProgressLocation, window } from 'vscode';
  +import { AzureTreeItem, openReadOnlyContent, TreeItemIconPath } from 'vscode-azureextensionui';
  import { DeployResult, LogEntry } from 'vscode-azurekudu/lib/models';
  import { formatDeployLog } from '../deploy/formatDeployLog';
  import { waitForDeploymentToComplete } from '../deploy/waitForDeploymentToComplete';
  @@ -123,8 +123,7 @@ export class DeploymentTreeItem extends AzureTreeItem<ISiteTreeRoot> {
  public async viewDeploymentLogs(): Promise<void> {
  await this.runWithTemporaryDescription(localize('retrievingLogs', 'Retrieving logs...'), async () => {
  const logData: string = await this.getDeploymentLogs();
  - const logDocument: TextDocument = await workspace.openTextDocument({ content: logData, language: 'log' });
  - await window.showTextDocument(logDocument);
  + await openReadOnlyContent(this, logData, '.log');
  });
  }
  