fix: Improved performance when printing logs in Output Channel

[Aerex]

Description

When running a dev command through the VSCode command palette it takes longer than usual for the logs to appear in the Output panel. This PR solves this problem by upgrading the vscode npm package to 1.64 which fixes the buffering issues that occurs in the Output Channel.

Callouts

• The typescript and mocha npm package were upgraded due to the upgrade to the vscode package
• There were some conditional logic changes to better ensure the Output Channel logs would appear (eg. if(outputChannel !== undefined) -> if(outputChannel))
• As of now, colors are not suppored in the output channel so colors have been diabled in all platforms. See git issue vscode#141556 for more information.
• Updated travis build to run unit tests under docker
• Used redhat ubi images to build base image for running vscode using xvfb (emulated X server)

Steps to Reproduce

1. Download the latest version of the IBM Cloud CLI extension if not already
2. Open the Command Palette (Ctrl-Shift-P or F1) and enter the command ibmcloud dev build
3. Verify that it takes longer than a minute for the entire logs to appear in the Ouput Channel

Solution

1. Prune any containers and images that was built in the Steps to Reproduce section
2. Install vsce npm package if not already: npm install -g vsce
3. Checkout PR branch
4. Run the command vsce package
5. Verify vsix package is built successfully
6. Open a starterkit project using VSCode
7. Go to Extension -> Install From VSIX` and select vsix file created in step 4
8. Reload VSCode when requested
9. Run ibmcloud dev build from Command Palette
10. Verify that performance for logs to appear have improved

[Aerex]

@steveclay @schmidtp0740 I was able to get the unit tests to run successfully in docker in the travis build. FYI

Ready for re-review

[steveclay]

@schmidtp0740 please review the Travis / devops changes before we merge this. 👍

[Aerex]

@schmidtp0740 Updated docker build to create image using redhat UBI. Ready for re-review. FYI @steveclay