bug/207_restrict_access_to_accounts_made_by_prefixes

[pcoello25]

• Fix issue #207
• No tests are required.
• e2e (unofficial) tests passed. pcoello25 accessing to /webhdfs/v1/user/pcoello25654:

$ curl -X GET "http://localhost:14000/webhdfs/v1/user/pcoello25654?op=liststatus&user.name=pcoello25" -H "X-Auth-Token: xxxxxxxxxxxxxxx"
Authorization error: user pcoello25 cannot access /webhdfs/v1/user/pcoello25654

info: pcoello25 is trying to access to /webhdfs/v1/user/pcoello25654 with the token xxxxxxxxxxxxxxx
error: Authorization error: user pcoello25 is not allowed to access /webhdfs/v1/user/pcoello25654

• Assignee: @frbattid

[frbattid]

LGTM