I see that you've blocked updates of byteorder due to concern for Rust 1.18 compatibility (#381, #380). However, in doing so, you're causing problems for all Rust versions:

error: failed to select a version for `byteorder`.
    ... required by package `bincode v1.3.2`

I know your change isn't technically a semver-breaking, but because of the way Cargo resolves dependencies, it is breaking builds (I have byteorder 1.3.2 elsewhere in the dependency tree, and cargo update can't deal with it).

Paradoxically, in a good-faith attempt to avoid breaking anyone, you've caused more breakage.

Please don't cause pain for all Rust users out of concern for users who use an outdated Rust version.