Updated mysql dependency

For some reason specifying "0.9.x" for mysql version pulled only their
latest branch (0.9.0) and not the latest tag (0.9.6).

I was receiving this error from 0.9.0:

> /home/mdwyer/Desktop/src/TAMU-btsync/iris/tamu-ldap-proxy/node_modules/node-dbi/node_modules/mysql/lib/mysql/net_constan
> ts.js:8
> module.exports = process.binding('net');
>                          ^
> Error: No such module
>     at Object.<anonymous> (/home/mdwyer/Desktop/src/TAMU-btsync/iris/tamu-ldap-proxy/node_modules/node-dbi/node_modules/
> mysql/lib/mysql/net_constants.js:8:26)
>     at Module._compile (module.js:449:26)
>     at Object.Module._extensions..js (module.js:467:10)
>     at Module.load (module.js:356:32)
>     at Function.Module._load (module.js:312:12)
>     at Module.require (module.js:362:17)
>     at require (module.js:378:17)
>     at Object.<anonymous> (/home/mdwyer/Desktop/src/TAMU-btsync/iris/tamu-ldap-proxy/node_modules/node-dbi/node_modules/
> mysql/lib/mysql/client.js:10:20)
>     at Module._compile (module.js:449:26)
>     at Object.Module._extensions..js (module.js:467:10)
>

This is fixed in
[1928c78](https://github.com/felixge/node-mysql/commit/1928c7800acc38cee2fe8c5b401b5afda64efc43).