Unify config.yaml source location in config.ru

[ravenium]

Hello,

Since certwriter is pretty intertwined with the rest of r509, it seems only fitting that it should look in the same spot as the rest of r509. Currently, there appears to be a spot to do this in the initialization, but it doesn't appear to be used:

---snip---
def initialize(app, config=nil)
@app = app

            unless config
                @config = YAML.load_file("config.yaml")
            else
                @config = config

--snip---

In config.ru, we have the following:

config_data = File.read("/custom/path/to/our/config.yaml").

It would seem to be a good idea if certwriter would reference this same path when it's called.

[reaperhulk]

Hi @ravenium, I'm hugely sorry about the delay in responding here. I didn't have notifications configured on this repo!

It's been awhile since I looked at the middleware (I spend more time in r509 itself obviously), but it looks like the config param is only used in the specs as a way to inject the configuration. Can you pass it in when calling use R509::Middleware::CertWriter in the config.ru?