Update launch library to use datetime

[DoloresHA]

Previous version used "start" from pylaunches which is a string that is not parsed by home assistant into a datetime. This change updates launch library to use the timestamp from pylaunches and parses it to make the launch_time attribute easier to template and automate with.

Description:

Modified launch library to pass datetime-parsable string instead of string.

**Related issue (if applicable): None

Example entry for configuration.yaml (if applicable):

Checklist:

• The code change is tested and works locally.
• [Not done] Local tests pass with tox. Your PR cannot be merged unless tests pass
• There is no commented out code in this PR.

If user exposed functionality or configuration variables are added/changed:

• [N/A] Documentation added/updated in home-assistant.io

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

• New dependencies have been added to the REQUIREMENTS variable (example).
• New dependencies are only imported inside functions that use them (example).
• New or updated dependencies have been added to requirements_all.txt by running script/gen_requirements_all.py.
• New files were added to .coveragerc.

If the code does not interact with devices:

• Tests have been added to verify that the new code works.

[houndci-bot]

line too long (92 > 79 characters)

[DoloresHA]

Fixed with commit 2.

[amelchio]

IMO this should preferably be changed in pylaunches.

[ludeeus]

I agree @amelchio
Are ISO formated acceptable?
example output:

{'stream': 'https://www.youtube.com/watch?v=aVIrgayWlI0', 'agency': 'United States Air Force', 'agency_country_code': 'USA', 'wsstamp': 1545573060, 'name': 'Falcon 9 Block 5 | GPS III SV01', 'start': '2018-12-23T14:51:00'}

'start': '2018-12-23T14:51:00'

Since this is used in an attribute I'm not sure if this apply home-assistant/architecture#39, but consistancy is good i guess :)

[DoloresHA]

@ludeeus I have no idea what the right answer is, presumably @amelchio does. I just knew that templates such as state_attr('sensor.next_launch', 'launch_time') didn't work as-is. Thank you for this awesome integration! I used it to automatically play the spacex launch today. :)

[ludeeus]

@DoloresHA I pushed version 0.2.0 of pylaunches with that change.
You can try that one, and see if that give you the control you are after.

[fabaff]

Why can't we use as_local from util/dt.py?

[DoloresHA]

@ludeeus hmm I updated my pylaunches dependency to 0.2.0, but
{{ as_timestamp(state_attr('sensor.next_launch', 'launch_time')) }} still renders "None" instead of a timestamp. :-/

[ludeeus]

@DoloresHA https://i.ibb.co/FDpknW6/image.png 🤷‍♂️

[DoloresHA]

@ludeeus I'm a doofus. I must have not actually rebooted or something? It's working for me as well. I've created PR #19570 to update the dependency and am closing this one. Thank you!