Td: Connect to TD
In RTD: Simple TD API Client

Connect to TD

1	Td(endpoint, apikey, user_agent, headers, http_proxy = NULL)

`endpoint`	Endpoint to TD API
`apikey`	API key for TD
`user_agent`	User-Agent as `character`. optional
`headers`	Default headres in a named `character` vector. optional
`http_proxy`	HTTP proxy setting. optional.

## Not run: 
client <- Td(
  endpoint = "api.treasuredata.com",
  apikey = "xxxxxx",
  http_proxy = "http://user:pass@proxy.domain.com:8080/"
)

## End(Not run)