Update ktools Dockerfile to use coreoasis/oasis_base:R_0_0_0_6 + clean up apt-get commands
Update ktools Dockerfile to use coreoasis/oasis_base:R_0_0_0_6 + clean up apt-get commands

OasisLMF/ktools,OasisLMF/ktools,OasisLMF/ktools,OasisLMF/ktools