Enable docker build layer caching

[paulbourelly999]

Types of Issue

• Anomaly report (something appears to not work correctly)
• [ x ] Enhancement request (describe the enhancement being requested)
• Other (please ensure the description clarifies why the issue doesn’t fall into either of the above categories)

Descriptive summary

Enable docker build layer caching to expedited build and pull process. This will enable CircleCI to use any cached build layers that are unaffected by changes and only build additional changed layers.

V2XHUB version where this issue was discovered

7.1

Expected behavior

Allow for CircleCI to cache build image layers

Actual behavior

Each docker build is executed from scratch

Steps to reproduce the actual behavior

1. Trigger CircleCI build process and compare sequential image build layers. They will currently all be completely unique.

Related work