fatbin: add Stat method (grailbio#10)

Stat provides fatbin.Info for the requested GOOS/GOARCH.

To be used in upcoming bigmachine changes.

bigslice: extract dump package from auto-log

Summary:
Extract a `diagnostic/dump` package from bigslice auto-log. This merges work that we paused in D33024 with the recently added auto-log, hopefully leaving us with the best of both worlds:

  - Create a new `diagnostic/dump` package that handles the actual dumping of diagnostics.  It has these changes from auto-log:
    - Expose API for parts of the dump to be registered externally (i.e. anything importing the package can add to the diagnostic dump).
    - Stop relying on HTTP. Given that we want as much reliability as possible when dumping diagnostics, bypassing HTTP as a layer probably gives us a better shot at it.
    - Rename some of the files in the dump to be more consistent with route names.
    - Accommodate use cases that the HTTP endpoints don't handle yet (which we'll fix separately), specifically that we can have multiple `bigmachine.B`s and `bigslice.Session`s in a single process.
    - Make the dump a gzipped tar archive instead of a zip file (just because that's what was in D33024).
    - Make the dump filename more informative: include executable name, start time, and duration from start time.
    - Add a few more diagnostic files: load, CPU, memory, and command-line.
  - Make auto-log use `diagnostic/dump`.
  - Expose an endpoint, `/debug/dump`, that allows you to retrieve a diagnostic dump on demand.

Test Plan:
Add and run unit tests.
Run manual tests.

Reviewers: pgopal, marius, joshnewman

Reviewed By: marius, joshnewman

Subscribers: smahadevan

Differential Revision: https://phabricator.grailbio.com/D37556

fbshipit-source-id: 736a799

base: mark finnicky tests as !unit

Summary:
There are some tests that require special OS conditions,
e.g., vanadium credentials, or a FUSE driver. We mark these
with !unit (they are in a sense integration tests). This way we
can run them with

	go test -tags=unit ./...

to have Travis CI tests pass.

Reviewers: ysaito, jcharumilind

Reviewed By: ysaito

Subscribers: smahadevan

Differential Revision: https://phabricator.grailbio.com/D37688

fbshipit-source-id: 7b0ff16

go.mod: tidy, patch update

base/cloud/url: move into grail.com

Summary:
cloud/url had only Encode and Decode methods for S3 URLs that are not
necessary, at least not now. Therefore, we can move them to the internal
repo for legacy compatibility with persisted objects with encoded keys,
etc. The two functions have been marked deprecated for end users to
consider removing their usage.

This change breaks the circular dependencies between grailbio/base,
grailbio/testutil, and yasushi-saito/zlibng.

Test Plan:
Unit tests.

Tested that S3 is indeed preserving all special characters by using
s3api directly.

Reviewers: ysaito, O15 scrms, marius, ajonnavithula

Reviewed By: ysaito, O15 scrms, ajonnavithula

Subscribers: smahadevan

Differential Revision: https://phabricator.grailbio.com/D37545

fbshipit-source-id: 58b8f83

update to the latest zlibng which now depends on the tagged grailbio/…

…testutil 0.0.1 (grailbio#4)

update to the latest zlibng which now depends on the tagged grailbio/…

…testutil 0.0.1 (grailbio#4)