[feat] Add support for time ranges longer than one hour

[edaemon]

To address #36, this adds the --iterate option. With this option the range between the start and end time can be longer than the one hour limit imposed by the Logpull API, and each one-hour block of that range will be requested separately. Requests are delayed to account for the current API request rate limits.

I don't have any experience writing Go, so please let me know wherever there's something inelegant/strange/wrong.

[jacobbednarz]

@edaemon do you mind getting CI green and I'll take a look at the code?

[edaemon]

@jacobbednarz Sure, of course. I took care of the formatting issue so it's green for 1.9.x through tip, but I'll have to take a bit to look into the 1.7.x and 1.8.x issues.

[edaemon]

@jacobbednarz This may just be my inexperience with Go showing, but from what I can tell the CI failures are in external packages. 1.7.x is failing in google.golang.org/api/transport/http/internal/propagation and 1.8.x seems to throw various warnings/failures from golang.org packages. I didn't make any changes related to any packages; I also noticed that the master branch build is failing with the same errors after #31 was merged.

Am I mistaken here or are these failures something external?

[jacobbednarz]

I'll double check. Go 1.7/1.8 might not support/ship those anymore. We've dropped 1.7/1.8/1.9 in a couple of other repositories due to a similar issue.

[jacobbednarz]

I've opened #38 to drop 1.7/1.8 from the build matrix.