Remove non-ASCII char from initializer template

Upon installing Doorkeeper I got a warning from my linter that there were non-ASCII characters in a US-ASCII encoded file generated by Doorkeeper. Running `iconv` against the file found the culprit, which has been replaced by a standard space character within this commit.
Merge pull request #384 from damien/patch-1

Remove non-ASCII char from initializer template
Little *Request code adjustments

* Don't include unneeded files.
* Implement some rubocop suggestions.
* Edit them so they look more alike.

There's repeated code to DRY out.
Travis Ruby 2.1 fix

https://github.com/travis-ci/travis-ci/issues/2220
Update to Ruby 1.9 hash syntax
Use single-quotes when string interpolation is not needed
Fix some indentation issues
Fix multi-line blocks syntax and introduce lambda literal syntax
Use fail instead of raise to signal exceptions
Remove redundant curly braces around hash parameters
Remove redundant returns
Remove useless commas
Use LOAD_PATH instead of $:
Fix litterals delimiters
Use Rails.logger instead of writing to stdout
Use %w for array of words
Remove a non-ascii symbol in comment
Fixe some style.
Use module_function instead of extending self
Merge pull request #390 from simonbnrd/code-cleanup

Style adjustments.