Change from update to revise

[rehandalal]

r?

[mythmon]

For context: @rehandalal and I discussed how update was confusing for a method that didn't directly change the object. For example, this test existed and was correct.

foo = RecipeFactory(name='first')
foo.update(name='second')
assert foo.name = 'first'

We decided revise was a better verb for this operation, since it creates new revisions.

[mythmon]

I didn't run this locally, because I'm confident in the tests to a refactor like this.

[chartjes]

+1 to the method rename, much clearer IMO