Keep Origin Style while cargo upgrade

[aurexav]

I don't want it to overwrite my format.

# origin
foo = { version = "0.1.0" }
# expect
foo = { version = "0.2.0" }
# actual
foo = "0.2.0

[augustocdias]

I would also expand this to the version specification.
I usually specify only "0.2" and I would like to keep my Cargo.tom that way.

[mgattozzi]

Another thing that would be nice, having run into this today, would be that if I use ^ or = at the beginning that they be preserved.

[epage]

Right now, we generically modify the dependency table. Really, we should be just overwriting the version field.

[epage]

#725 fixed this.