Rollup merge of rust-lang#61771 - ehuss:update-cargo, r=alexcrichton

Update cargo

Update cargo

19 commits in 545f354259be4e9745ea00a524c0e4c51df01aa6..807429e1b6da4e2ec52488ef2f59e77068c31e1f
2019-05-23 17:45:30 +0000 to 2019-06-11 14:06:10 +0000
- Stabilize publish-lockfile. (rust-lang/cargo#7026)
- change package cache lock message (rust-lang/cargo#7029)
- Fix documenting an example. (rust-lang/cargo#7023)
- Fix nonconcurrent tests (rust-lang/cargo#6900)
- Update git2 crates for libgit2 0.28 (rust-lang/cargo#7018)
- fix bunch of clippy warnings (rust-lang/cargo#7019)
- Ignore remap-path-prefix in metadata hash. (rust-lang/cargo#6966)
- Don't synthesize feature diretives for non-optional deps (rust-lang/cargo#7010)
- Handle pipelined tests of libraries (rust-lang/cargo#7008)
- Import the cargo-vendor subcommand into Cargo (rust-lang/cargo#6869)
- Remove unnecessary outlives bounds (rust-lang/cargo#7000)
- Catch filename output collisions in rustdoc. (rust-lang/cargo#6998)
- the testing SAT solver was messed up by a refactor (rust-lang/cargo#6995)
- Add some hints to the docs for `cfg()` targets (rust-lang/cargo#6990)
- Test the Resolver against the varisat Library (rust-lang/cargo#6980)
- Update changelog. (rust-lang/cargo#6984)
- Update cache-messages tracking issue. (rust-lang/cargo#6987)
- zsh: Add --all-targets option to cargo-check and cargo-build (rust-lang/cargo#6985)
- Fix typo (rust-lang/cargo#6982)