Rollup merge of rust-lang#76498 - ehuss:update-cargo, r=ehuss

Update cargo

8 commits in 126907a7cfccbe93778530e6a6bbaa3adb6c515c..875e0123259b0b6299903fe4aea0a12ecde9324f
2020-08-31 20:42:11 +0000 to 2020-09-08 20:17:21 +0000
- Lowercase and remove periods in error messages for consistency (rust-lang/cargo#8655)
- Allow running build-man.sh from any directory (rust-lang/cargo#8682)
- docs: add details for cargo check pass where cargo build fail (rust-lang/cargo#8677)
- Fix nightly exported_priv_warning test. (rust-lang/cargo#8678)
- fix mdbook test with ```ignore/text/sh/console (rust-lang/cargo#8674)
- End CACHEDIR.TAG with newline (rust-lang/cargo#8672)
- Fixed the fossil repo initialization actually run commands (rust-lang/cargo#8671)
- Remove asciidoc attribute in cargo-metadata man page. (rust-lang/cargo#8670)

Author: Dylan-DPC