Stdin input throwing unpretty error when config is missing

[nzakas]

(Split out from #7144)

Tell us about your environment

• ESLint Version: master
• Node Version: 4.4.2
• npm Version: 2.15.0

What parser (default, Babel-ESLint, etc.) are you using? default

Please show your full configuration: n/a

What did you do? Please include the actual source code causing the issue.

Ran this in the command line in a directory without a configuration file.

$ echo 'var x = "y";' | eslint --stdin

What did you expect to happen?

I expected to see the pretty message telling me there is no config file.

What actually happened? Please include the actual, raw output from ESLint.

I get an ugly message telling me a config file is missing:

No ESLint configuration found.
Error: No ESLint configuration found.
    at getLocalConfig (/Users/cowboyd/.nvm/versions/node/v4.2.3/lib/node_modules/eslint/lib/config.js:162:35)
    at Config.getConfig (/Users/cowboyd/.nvm/versions/node/v4.2.3/lib/node_modules/eslint/lib/config.js:256:22)
    at processText (/Users/cowboyd/.nvm/versions/node/v4.2.3/lib/node_modules/eslint/lib/cli-engine.js:222:33)
    at CLIEngine.executeOnText (/Users/cowboyd/.nvm/versions/node/v4.2.3/lib/node_modules/eslint/lib/cli-engine.js:749:26)
    at Object.execute (/Users/cowboyd/.nvm/versions/node/v4.2.3/lib/node_modules/eslint/lib/cli.js:174:42)
    at /Users/cowboyd/.nvm/versions/node/v4.2.3/lib/node_modules/eslint/bin/eslint.js:57:36
    at ConcatStream.<anonymous> (/Users/cowboyd/.nvm/versions/node/v4.2.3/lib/node_modules/eslint/node_modules/concat-stream/index.js:36:43)
    at emitNone (events.js:72:20)
    at ConcatStream.emit (events.js:166:7)
    at finishMaybe (/Users/cowboyd/.nvm/versions/node/v4.2.3/lib/node_modules/eslint/node_modules/concat-stream/node_modules/readable-stream/lib/_stream_writable.js:475:14)

[not-an-aardvark]

Working on this.