[Openid-specs-fapi] Issue #464: Review casing of keywords (openid/fapi)

[Travis Spencer]

New issue 464: Review casing of keywords
https://bitbucket.org/openid/fapi/issues/464/review-casing-of-keywords

Travis Spencer:

`fapi-grant-management.md` line 89 \(where it says `the authorization server shall handle the grant`\) uses `shall` in lower-case. That and other parts of the document should be reviewed to see if the proper casing of the keywords are being used.

_NOTE_: The preamble makes reference to BCP14, RFC2119, and RFC8174 where it says that only when these keywords are in all capitals shall they be considered special.