Invenio-admin

- This release was available on PyPI for about 1 hour, but was removed because
it was breaking compatibility. Instead v1.3 was released.

- Minimum version of Invenio-Accounts bumped to v1.1.4 due WTForms moving the
email validation to an optional dependency.
- Minimum version of Flask-Admin bumped to v1.5.6 due to a fixed SQLAlchemy
1.3.6 compatibility issue

- Changes flask dependency to centrally managed

- Minimum version of Invenio-Accounts bumped to v1.1.4 due WTForms moving the
email validation to an optional dependency.
- Minimum version of Flask-Admin bumped to v1.5.6 due to a fixed SQLAlchemy
1.3.6 compatibility issue
- Maximum version of Invenio-Access set to 1.4.0 due to circular dependency.
- Minimum version of Flask bumped to 1.0.4 and from six to 1.12.0 due to
dependency management missmatches.
- Maximum version of Flask-Login set to 0.5.0 due to dependency management
missmatches.

- Fixes werkzeug deprecation warning.

- Minimum version of Flask-Admin bumped to v1.5.3 due to Cross-Site Scripting
vulnerability in previous versions.