Remove the last traces of beaker.

There were still some traces of beaker around:
- docs: replaced by reference to itsdangerous.
- paste configs: Wiped away.
- config_spec.ini: wiped.
- test_mgoblin_app.ini: also wiped.

mediagoblin/tests/test_mgoblin_app.ini

@@ -23,10 +23,6 @@ base_url = /mgoblin_media/
 [storage:queuestore]
 base_dir = %(here)s/test_user_dev/media/queue
 
-[beaker.cache]
-data_dir = %(here)s/test_user_dev/beaker/cache/data
-lock_dir = %(here)s/test_user_dev/beaker/cache/lock
-
 [celery]
 CELERY_ALWAYS_EAGER = true
 CELERY_RESULT_DBURI = "sqlite:///%(here)s/test_user_dev/celery.db"

mediagoblin/tests/test_paste.ini

@@ -9,7 +9,6 @@ use = egg:Paste#urlmap
 
 [app:mediagoblin]
 use = egg:mediagoblin#app
-filter-with = beaker
 config = %(here)s/mediagoblin.ini
 
 [app:publicstore_serve]
@@ -20,14 +19,6 @@ document_root = %(here)s/test_user_dev/media/public
 use = egg:Paste#static
 document_root = %(here)s/mediagoblin/static/
 
-[filter:beaker]
-use = egg:Beaker#beaker_session
-cache_dir = %(here)s/test_user_dev/beaker
-beaker.session.key = mediagoblin
-# beaker.session.secret = somesupersecret
-beaker.session.data_dir = %(here)s/test_user_dev/beaker/sessions/data
-beaker.session.lock_dir = %(here)s/test_user_dev/beaker/sessions/lock
-
 [celery]
 CELERY_ALWAYS_EAGER = true