Add new data export fields to FullStory tap

[jameremo]

Some good progress was made on addressing this issue in #6. If anyone wants to press forward on that PR that would be helpful otherwise @jameremo will get to it when/if they can.

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In recent months, FullStory has added a few additional fields to its data export. The new fields are:

LoadDomContentTime (int64)
LoadEventTime (int64)
LoadFirstPaintTime (int64)
PageClusterId (int64)

(note that as of this writing, PageClusterId has likely not been released yet, but it should be out within the next week or two).

These new fields should be added to the tap's schema. Please let me know if I can answer questions or assist in any way.

[KAllan357]

Thanks for the issue report @jameremo. Would you be open to adding these fields to the schema and opening a PR?

[jameremo]

@KAllan357 I'll try to find some time, likely next week, to open a PR. IIUC the code changes will be small (in the schema file only), but I am a Python and Singer noob and will need some extra time to get everything set up and properly tested prior to submission.

[jameremo]

@KAllan357 Please see #6. While testing I found a few issues with the rate limiting, and I've made some comments on the fixes that hopefully make my intentions clear.

[timvisher]

@jameremo Thanks for submitting the PR! :)

I'll try to review it asap.