Thanks to Joern SchneeweiszStaff Security Engineer, Security Research | GitLab for raising the issue

Added --npm_options option to customize npm behavior

Ubuntu Xenial reached EOL in April 2021. Some of the Ubuntu packages this
image required were being pulled due to the EOL causing build failures.
As such, the image was updated to use the next Ubuntu verseion.

Some minor image cleanup are also included in this commit.

[#178471230]

Signed-off-by: Jason Smith <jsmith@pivotal.io>
Signed-off-by: Jeff Pun <jjun@pivotal.io>

During the Ubuntu Bionic upgrade, the default timezome was set to
America/Toronto in order to install the new version of Composer. The
newer version of composer requires a timezome to bet set in order to
install.

However, the test assumes LF runs on GMT timezome image.  So, the
default timezone has been updated.

[#178471230]

Upgrade Docker image to use Ubuntu Bionic

The GPG server suggested by the Swift docker image sample has not been
responding.

So, the public keys have been dowloaded and saved in the repo. These
keys will be imported instead of dowloaded.

[#178674224]