feat(rsconnect): update pin title at content level

[machow]

• Correctly handle title updates on RStudio Connect #30
• Double check RSC index.html and metadata #40

TODO:

• tests are up to date, but new tests are needed to cover the issues above
• be sure to include one for..
  • of apply_suffix arg in drivers
  • MetaFactory.create using a base_directory
  • the files and name attribute for RSC pin meta: see Ensure that RSC meta name attribute is full pin name #73
  • test of title updating

SURPRISE TODO:

• Mac OSX tests periodically fail due to github API rate limiting #74