Changed symbol to module parameter for the formatter.

This requires the Logger to be initialized with a LogStash4r::Formatters

Signed-off-by: Jesse Szwedko <j.szwedko@modcloth.com>
Injecting socket to logger

Signed-off-by: Sheena McCoy <sp.mccoy@modcloth.com>
Refactoring formatter specs

To their own module spec files (just checking that the logger
delegates). Also moved the logger spec into the appropriate
subdirectory.

Signed-off-by: Sheena McCoy <sp.mccoy@modcloth.com>