* native-tls: fix use of non-fmt panic in tests
* fix some misc. clippy lints
This branch fixes a number of lints. The most important one was the use
of a non-`format_args!` expression in a `panic!` macro, which generates
a compiler warning in recent Rust toolchains, which is breaking the CI
`cargo check` run on PR #64.
While I was here, I also fixed some miscellaneous Clippy lints, mostly
in tests. These include:
* Use of `clone()` on `SocketAddr`s (which implement `Copy`)
* Unnecessary single-path-segment imports (which probably used to be
`extern crate`s in earlier Rust?)
* `'static` lifetimes in `const` type annotations (`const`s always have
the `'static` lifetime)
None of these were breaking the build on CI, but I figured I'd address
them while I was fixing other lints.
Signed-off-by: Eliza Weisman <eliza@buoyant.io>
