update JPA annotations of lab8 to fix some mistakes
update of assignment 3, update of lab10 codes
added lab 11 example
updated code for lab11
added postman export
added clients for document service, fixed bugs
updated assignment 3 details, fixed bugs in jpa of lab 8 example
updated also slides
Merge branch 'master' of https://github.com/cdparra/introsde2013