Update csl-styles gem

[jcoyne]

Currently we pin the gem at 1.0.1.8, even though 1.0.1.9 has been released.

Updating this gem may alter the formatting of citations generated from
source data, which is cached in our database and displayed on profiles pages.
Citation formatting is embedded in tests, so updating this gem may break tests
(legitimately) and will also change how publications appear on profiles pages to end users. Consult stakeholders before updating.

Making this migration may involve regenerating all the cached data.