This commit replaces the `slog` family of crates used by `wasm-pack`
with the `log` crate plus `env_logger`. This also means that by default
`wasm-pack` also won't create a `wasm-pack.log` file in the current
directory. Enabling logging will now be done through
`RUST_LOG=wasm_pack` instead of `-v` flags.
Closes#425
This commit removes the internal `Error` type in favor of exclusively
using the `failure::Error` type, simplifying error construction in a
number of locations and reducing the number of error types in play.
The standard library version of an `RwLock` may get poisoned if a thread
panics that holds a write lock. The `RwLock` from parking_lot [1] does
not get poisoned it instead released the lock on a panic. This allows us
to simplify the `ProgressOutput` API since it no longer returns any
errors. No more panics can occur on `ProgressOutput::drop()`. The
`Error` enum can thus be simplified as well because there is no need to
convert `PoisonErrors` anymore.
[1] https://github.com/Amanieu/parking_lot
ashley williams