Add quotes to returned error messages to make them parseable as hash.

Controlled by presence of environment variable MEMBRANE_ERROR_USE_QUOTES
Handle nested schema when quoting error message
Merge pull request #4 from mweaverh/master

Add quotes to error messages to make them parseable as hash.
Bump version to 1.1.0

* New functionality introduced in commit 56fd779b, merging in PR #4:
  MEMBRANE_ERROR_USE_QUOTES environment variable affects validation
  error message formatting.

Signed-off-by: Ruth Byers <rbyers@pivotallabs.com>
Add Code Climate badge to README.

Signed-off-by: Ruth Byers <rbyers@pivotallabs.com>