Updated README. - Modify URLs to POC endpoints to include '/fcrepo' - Remove dead link and paragraph regarding the proof-of-concept/README.md.
Updated README.
- Modify URLs to POC endpoints to include '/fcrepo'
- Remove dead link and paragraph regarding the proof-of-concept/README.md.

fcrepo4-labs/fcrepo-api-x,birkland/fcrepo-api-x,emetsger/fcrepo-api-x,birkland/fcrepo-api-x,birkland/fcrepo-api-x,fcrepo4-labs/fcrepo-api-x,birkland/fcrepo-api-x,emetsger/fcrepo-api-x,emetsger/fcrepo-api-x,fcrepo4-labs/fcrepo-api-x,fcrepo4-labs/fcrepo-api-x,birkland/fcrepo-api-x,emetsger/fcrepo-api-x,fcrepo4-labs/fcrepo-api-x,emetsger/fcrepo-api-x