* Remove tarball.WithCompressedCaching flag to resolve OOM Killed error
Large images cannot be build as the kaniko container will be killed due to an OOM error. Removing the tarball compression drastically reduces the memory required to push large image layers. Fixes#1680
This change may increase the build time for smaller images. Therefore a command line option to trigger the compression or a more intelligent behaviour may be useful.
* Add new command line flag to toggle compressed caching
* Add unittest for build with --compressed-caching command line flag set to false