Setting Content-Type of response to text/plain. Related to Issue #68
Implement authentication to query interface endpoint

Fixes#79
Implement HEAD request method to query interface endpoint.
Fixes #80
Fix implement head request at Query Interface endpoint
Fixing implementation of HEAD request to query interface endpoint
Fixing query interface output to occi format

Fixes #81
Fixing bug of allowing to add same image to fogbow resources more than
one time.

Fixes #82
Fixing query interface response format
Adding log for query interface
Fixing location property of resources (adding / at the end)

Removing requirement of Content-Type text/occi of Query Interface
endpoint

Fixes #83
Adding resource_tpl and os_tpl for query interface endpoint
Adding rel property to request Resource kind
Changing request resource term for testing
Adding debug log
Implement supporting of multiple values to same Category and
X-OCCI-Attribute headers.

Fixes #84
Support occi.core attributes.

Fixes #85
Fixing creation of Category from a string
Impleminting the use of federationIdentityPlugin. Fixing tests.
Refatoring constants.
Refatoring Cli. Accepting other credentials.
Fix location of created requests

Fixes #88