* added scopes on integrations, scopes are:
- repo only
- repogroup children only
- root repos only
- global (any repo)
* integrations schemas now have separate section for the
settings (eg. slack) and options (eg. scope/enabled)
* added descriptions to integration types
* added icons to integration types
* added 'create new' integration page
* added scope of integration to integrations list
* added breadcrumbs for each repo/repogroup/global integrations pages
* added sorting to integrations list
* added pagination to integrations list
* added icons to integrations list
* added type filter to integrations list
* added message to integrations list if none we found
* added extra permissions check on integrations views
* db migration from 56 => 57 - adds child_repos_only field
* added tests for integrations triggered on events
* added tests for integrations schemas
* added tests for integrations views for repo/repogroup/admin
* added db migration for integration table, version 55
* added integrations views/templates/models
* added slack integration
* added h.url.current() support for pyramid only contexts
* added issues extractor for commit messages
* renamed repo-deleted/repo-created to repo-delete/repo-create
* removed marshmallow
* added serialization for events to static dicts of data
* added lazy_ugettext for translation of start time string
