Migrate output towards the 1.0 strategy

This commit is the first in what is hopefully a series to help move
`wasm-pack`'s CLI output and interactions to a "1.0 status". This was
[discussed at the recent Rust All Hands][discussion] where the salient
points we ended up extracting were:

* At all times if a user is waiting for `wasm-pack` to finish it should
  be clear what's being waited on.
  * As an example, Cargo's own output shows what crate is being built.
  * As another example, something that always takes only a handful of
    milliseconds to complete doesn't need an informational message.
* The final output products of a command should always be clear and
  printed. For example the output location of artifacts should always be
  printed.
* The `wasm-pack` CLI tool should use "progressive enhancement" to
  incrementally detect features of the output it can use (like colors,
  emoji, etc) but always work in the absence of these features. This'll
  help us support a wide range of use cases and terminals.

The goal of this commit is to not get us all the way there but start us
down the path to satisfying these goals. To that end the major change
here is to remove the dependency on `indicatif`. Using `indicatif`
requires that all output is piped through the `indicatif` crate itself,
which causes the third item here to not work for one of the main parts
of `wasm-pack build`, the `cargo` pieces. Cargo (and the Rust compiler)
are unable to use thir own tools for progressive enhancement when the
output is captured and sent through `indicatif`.

Lots more refactoring will be needed internally to fully polish off the
input/output to a "1.0 status", but this is hopefully a good start!

[discussion]: https://gist.github.com/fitzgen/23a62ebbd67574b9f6f72e5ac8eaeb67#file-road-to-wasm-pack-1-0-md