Add support for SHOW CREATE TABLE

[TheMP]

Apparently one of the drivers I use requires this command to be working:

Query:
SHOW CREATE TABLE plyql1.test
If you believe this query should work please create an issue on PlyQL and include this section
Issue url: https://github.com/implydata/plyql/issues

[Gael Grosch]

I encountered this same problem with Metabase. It seems the clojure jdbc driver requires this command.

[David Gee]

Please note that this project is now deprecated. Please see the Druid SQL docs for information on using SQL syntax with Druid.