Improve analytics integration

[philfreo]

1. We can probably remove

   making.close.com/package.json

   Line 13 in 684fa1e

   "gatsby-plugin-google-analytics": "^2.3.14",

   - we shouldn't be bundling GA at all since we send through Segment.

2. The delayLoad feature that we have enabled is kind of weird. At least be aware of it when debugging – Segment's JS doesn't even load at all when visiting https://making.close.com/ until after you start scrolling the page (even clicking the first post doesn't seem to register the initial homepage view). We should probably just disable it.