This commit updates the `sourcecred load` command so that it also
automatically runs PageRank on completion.
The implementation is slightly hacky, in that it prints two sets of
task status headers/footers to console, for reasons described in a
comment in the source code. The user-visible effect of this hack can
be seen below:
```
❯ node bin/sourcecred.js load sourcecred/example-github
Starting tasks
GO load-git
GO load-github
DONE load-github
DONE load-git
Overview
Final result: SUCCESS
Starting tasks
GO run-pagerank
DONE run-pagerank
Overview
Final result: SUCCESS
```
It would be good to clean this up, but for now I think it's acceptable.
Note that it is not safe to assume that a PagerankGraph always exists
for repos that are included in the RepoIdRegistry. The repo gets added
to the registry before the pagerank task runs. Consumers that are
loading the `PagerankGraph` can just check that the file exists, though.
Test plan: I've added unit tests that verify that the right tasks are
generated. Most importantly, the snapshot of the results of `sourcecred
load` now include a snapshotted pagerank graph.
(The snapshot was updated via `UPDATE_SNAPSHOT=1 yarn test --full`.)
Further progress on #967.
7efcc13618