Fix a few typos in the shibboleth doc
Fix a few typos in the shibboleth doc

Fixed the following:
- incorrect path /etc/shibboleth in an example
- authentication spelled incorrectly
- Shibboleth not capitalized once

Change-Id: Idfb55ef7da0d52ad2d468525363973f2722ed347

rodrigods/keystone,jamielennox/keystone,ilay09/keystone,idjaw/keystone,MaheshIBM/keystone,reeshupatel/demo,rushiagr/keystone,ging/keystone,ilay09/keystone,maestro-hybrid-cloud/keystone,vivekdhayaal/keystone,nuxeh/keystone,UTSA-ICS/keystone-kerberos,jamielennox/keystone,cernops/keystone,rajalokan/keystone,openstack/keystone,ilay09/keystone,cernops/keystone,roopali8/keystone,rushiagr/keystone,mahak/keystone,jumpstarter-io/keystone,nuxeh/keystone,maestro-hybrid-cloud/keystone,blueboxgroup/keystone,jonnary/keystone,rajalokan/keystone,vivekdhayaal/keystone,roopali8/keystone,takeshineshiro/keystone,himanshu-setia/keystone,jonnary/keystone,reeshupatel/demo,nuxeh/keystone,idjaw/keystone,mahak/keystone,promptworks/keystone,klmitch/keystone,ajayaa/keystone,klmitch/keystone,rushiagr/keystone,dstanek/keystone,promptworks/keystone,blueboxgroup/keystone,ajayaa/keystone,ging/keystone,dims/keystone,MaheshIBM/keystone,mahak/keystone,jumpstarter-io/keystone,jumpstarter-io/keystone,openstack/keystone,dstanek/keystone,rodrigods/keystone,himanshu-setia/keystone,dims/keystone,vivekdhayaal/keystone,reeshupatel/demo,UTSA-ICS/keystone-kerberos,openstack/keystone,takeshineshiro/keystone,dstanek/keystone,promptworks/keystone,rajalokan/keystone