submodules: update clippy from c63b6349 to 1b89724b
submodules: update clippy from c63b6349 to 1b89724b

Changes:
````
Really fix issue number in `map_clone` test
Fix issue number in `map_clone` test
Remove `map_clone` fixed known problem
Fix `map_clone` bad suggestion
Add run-rustfix to unnecessary_fold
Add run-rustfix to unit_arg test
Add run-rustfix for types test
Add run-rustfix to starts_ends_with
Add run-rustfix to replace_const test
Add run-rustfix to redundant_field_names
Missing docs: don't require documenting Global Asm items.
Add run-rustfix for precedence test
Add run-rustfix to mem_replace test
Add run-rustfix to map_clone test
Add run-rustfix to large_digit_groups
Add run-rustfix to into_iter_on_ref
Add run-rustfix to infallible_destructuring_match
Add rustfix to inconsistent_digit_grouping test
Add run-rustfix to explicit_write test
Add run-rustfix to excessive_precision test
Add run-rustfix to duration_subsec test
Disable deprecated_cfg_attr lint for inner attributes
Add run-rustfix to collapsible_if test
Update Readme
Update Readme for (arguably) better readability
rustup: the features if_while_or_patterns has been stabilized
Fix comments in clippy_lints/src/len_zero.rs
readme: update travis badge to reflect migration from travis-ci.org to travis-ci.com
Remove all copyright license headers
Move cast_ref_to_mut list to correctness group
Rustftmt
Don't import ty::Ref in cast_ref_to_mut lint
Move a hint to an error message in cast_ref_to_mut lint
Add a note to cast_ref_to_mut lint
Use ty::Ref instead of ty::TyKind::Ref
cast_ref_to_mut lint
Add missing ` in default lint
Improve tests and exclude nested impls
Update `unwrap_get` code review suggestions
Update known problems
Restrict use_self on nested items
Improve `get_unwrap` suggestion
````

graydon/rust,aidancully/rust,aidancully/rust,aidancully/rust,graydon/rust,graydon/rust,aidancully/rust,graydon/rust,aidancully/rust,aidancully/rust,graydon/rust,graydon/rust