Planning to release a v2.1.0 over the next week or so (target 6th June 2018).

Reminders for me:

• Open a v2.1.1 milestone
• Ensure the version switcher code is in-place in the iris docs (@pelson re Iris version switcher scitools.org.uk#191)
• Update the what's new
  • Ensure the docs/iris/src/_templates/index.html link to the what's new is updated
  • Write a what's new for Add Albers Equal Area Projection and some test as per #2496 #2943.
  • Write a what's new for iris.quickplot: Ensure labels and plot use the same axes #3010.
  • Double check that the what's new is representative of all PRs that actually got merged.
• Ensure the URL of the image in the README is updated as per Improve the appeal of the landing pages (docs and README) #3040 (comment)
• Ensure a what's new directory exists for v2.2 (and think about whether this process continues to make sense) (note: this doesn't make sense, as you have to have a file in order to add the directory, and there isn't any what's new yet. Personally, I see the what's new stuff flawed. I'll address this over the next few weeks, but not for v2.1)
• Update the version strings Prepare for 2.1.0 release #3051 (also see Release 2.1.0 #3038 (comment))
• Update the cf-standard names
• Merge any existing release branches (and close some off)
• Push docs to scitools.org.uk
• Push sdist to pypi
• Update conda-forge
• Announce on mailing-list
• Write this down in a release checklist
• Close the v2.1.0 milestone