Upgrades the edition, with changes primarily performed by
`cargo fix --edition`.
In order to keep the changes to a minimum, this doesn't include
automated idiom fixes (i.e. `cargo fix --edition-idioms`).
This is needed to unblock the edition upgrade for the RSA crate:
https://github.com/RustCrypto/RSA/pull/135
This bumps the minimum rustc to 1.8.0, "fixing" #257. I normally
consider this a breaking change, but we were already broken due to
external factors, for which I couldn't find a workaround.
This adds 1.15.0 to the CI matrix to build stable num-derive. We still
need nightly to run its tests though, because of compiletest_rs, and
dev-dependencies can't be optional.
The testing scripts are moved from .travis/ to ci/, as they don't really
need to be hidden. It's also now consolidated into one test_full.sh
which considers $TRAVIS_RUST_VERSION as needed.
Making bignum optional allows skipping the rustc-serialize and rand
dependencies too, and it makes a big difference in num's build time.
With default (all) features, clean build time including dependencies: 27
seconds.
With no default features, clean build time including dependencies (none):
5 seconds.
