safe_vault 0.18.0

Implementation of the 'Vault' node for the SAFE Network.
Documentation
#
# @note: The README.md file is included to ensure the ./target/release/
#        directory is copied to the container. If the safe_vault executable
#        doesn't exist on the host machine and the README.md file is not
#        included in the build, it will fail.
#
target/
!target/release/README.md
!target/release/safe_vault