Upgrade sendgrid to 5.5.0

[fabaff]

Description:

Changelog: https://github.com/sendgrid/sendgrid-python/blob/master/CHANGELOG.md#551---2018-08-16

notify:
  - name: sendgrid
    platform: sendgrid
    api_key: !secret sendgrid_api
    sender: !secret sendgrid_sender
    recipient: !secret sendgrid_recipient

Message sent with "Call Service"

{"message": "The sun is {% if is_state('sun.sun', 'above_horizon') %}up{% else %}down{% endif %}!"}

Checklist:

• The code change is tested and works locally.
• Local tests pass with tox. Your PR cannot be merged unless tests pass

If the code communicates with devices, web services, or third-party tools:

• New dependencies have been added to the REQUIREMENTS variable (example).
• New or updated dependencies have been added to requirements_all.txt by running script/gen_requirements_all.py.