README.md: Convert 'boot camp' -> 'workshop'

Following Amy Brown's [1]:

> We borrowed the "bootcamp" terminology from Hacker Within and also
> various fitness training camps, but as we branch out into parts of
> the world with a more violent recent history I'm less comfortable
> with the term.

The consensus on that issue was to change back to our old 'workshop'
terminology.  The swcarpentry/bc repository hasn't made the shift yet,
but there's no reason I can't embrace the future here ;).

[1]: https://github.com/swcarpentry/bc/issues/240
Merge branch 'master' into bc-namespaced

* master:
  README.md: Convert 'boot camp' -> 'workshop'
Merge branch 'bc-namespaced' of git://tremily.us/swc-setup-installation-test into installation-test-bc-namespaced

* 'bc-namespaced' of git://tremily.us/swc-setup-installation-test:
  README.md: Convert 'boot camp' -> 'workshop'

Conflicts:
	setup/README.md

The conflics were due to Ivan's 'boot camp' -> 'bootcamp' changes [1]
which I hadn't pulled into my upstream installation-test branch.  The
end result (using 'workshop' to refer to our sessions) is the same,
but my upstream history just skips the 'bootcamp' phase.

[1]: https://github.com/swcarpentry/bc/pull/174
Init. commit of (medical) image processing ipynb.
Add height to Eventbrite iframe

and values for when using two rooms.

**The height provided isn't suitable for small screens.**

Close #493.
Made changes suggested by Will Trimble - change Lena for Sally Ride.
Downsampled image to sensible size and removed references to SciPy Lena.
Simplified introduction by removing complicated colourbar placement stages.
Finished cleaning up IPYNB to show Gaussian fit to background.
Starting to write up instructor's guide
Reading list for training course
Starting to outline the introduction to the course
Adding headers
Building instructor's guide with everything else
Link to Bret Victor's essay
Starting to block out a proper introduction
More work on lessons
Create new lesson 02 on forking

Create an empty lesson on forking and bump the other lesson numbers up accordingly.
add new extra lesson about forking

Add the first draft of a new lesson about forking. The lesson covers creating a fork, creating pull requests, and reasons for using a fork instead of working off of one repo. Leaves out the details of code review.

This encompasses most of the material that is in lesson 03. The plan is to rewrite 03 to focus on pull requests and code review. It should cover using pull requests from different branches in the same repo as well as between forks.
clarify early why a fork is necessary

to address comment #1 on pull request #517, this makes explicit that you won't
always be able to push directly to repositories other people have made.