* Fix typo in documentation
* Update fdb-go-install.sh for new release tags
* Exclude FoundationDB bindings from vendoring, delete vendored copy
FoundationDB bindings are tightly coupled to the server version and
client library version used in a specific deployment. Bindings need
to be installed using the fdb-go-install.sh script, as documented in
the foundationdb backend documentation.
* Add TLS support to FoundationDB backend
TLS support appeared in FoundationDB 5.2.4, raising the minimum API version
for TLS-aware FoundationDB code to 520.
* Update documentation for FoundationDB TLS support
