feat(notification): add Python runtime version information to device data

[tomlongridge]

adds version string (from platform.python_version()) to device.runtimeVersions.python payload

Goal

Augments reporting with the version of Python in use when an event occurred in case of issues in a specific Python version.

Design

Added data to device.runtimeVersions.python as per other notifiers.

Changeset

Changed

• Added new field in configuration, set to platform.python_version() on init
• notification and sessiontracker use this data in their payloads

Tests

• Added unit tests for the presence of the data
• Confirmed data is there in example project

Review

For the submitter, initial self-review:

• Commented on code changes inline explain the reasoning behind the approach
• Reviewed the test cases added for completeness and possible points for discussion
• A changelog entry was added for the goal of this pull request
• Check the scope of the changeset - is everything in the diff required for the pull request?
• This pull request is ready for:
  • Initial review of the intended approach, not yet feature complete
  • Structural review of the classes, functions, and properties modified
  • Final review

For the pull request reviewer(s), this changeset has been reviewed for:

• Consistency across platforms for structures or concepts added or modified
• Consistency between the changeset and the goal stated above
• Internal consistency with the rest of the library - is there any overlap between existing interfaces and any which have been added?
• Usage friction - is the proposed change in usage cumbersome or complicated?
• Performance and complexity - are there any cases of unexpected O(n^3) when iterating, recursing, flat mapping, etc?
• Concurrency concerns - if components are accessed asynchronously, what issues will arise
• Thoroughness of added tests and any missing edge cases
• Idiomatic use of the language

[tobyhs]

The code looks fine, but I haven't had too much time to check why the build is failing and if its related.

I pushed a branch to trigger a build and that passed, so there is a chance that it is related to the changes (but I'm not seeing it yet).

[tobyhs]

As far as I know, platform.python_version() returns a string; is there a particular reason you're using str here?

[tomlongridge]

Ah, I misread the docs when it said defaults to 0 for patch version.

TBH, it was an optimistic addition to try and resolve the build failures. I thought it was happening on Travis for py34 only, but the build history seems to suggest these failures are randomly happening but only on this branch.

They are all TypeError: string indices must be integers errors when examining the payload. However I cannot see how adding a new field to the dict should cause this. I might need to dig into the FilterDict code to see if this is somehow causing some unexpected changes to the structure.

[tobyhs]

I can't tell if you were planning on removing the str call or not.

[tobyhs]

lgtm as a re-build passed

[tobyhs]

lgtm