Display scope in html examples

Closes #116
Merge branch 'master' of github.com:zipmark/rspec_api_documentation
Filter request and/or response headers by configuration

New configuration variables:
- response_headers_to_include
- request_headers_to_include
Fixing curl generation when nil header is passed
Merge pull request #119 from NZN/fix_curl_generation

Fixing curl generation when nil header is passed
Filter request and/or response headers by configuration

New configuration variables:
- response_headers_to_include
- request_headers_to_include
Refactor
Merge pull request #118 from Pact/header-filters

Filter request and/or response headers by configuration
Merge branch 'master' into change-json