feat(cops): Add support for running unsafe cops with latest RuboCop

Latest version of RuboCop now only performs auto-corrections from "safe"
cops when given the `--auto-correct`/`-a` option. To run
auto-corrections from all cops, including "unsafe" ones, you must now
pass in `--auto-correct-all`/`-A` instead.

The new `rubocopfmt-include-unsafe-cops` defcustom defaults to no `nil`,
for backwards compatibility. Turn on unsafe cops by setting it to `t`.

README.md

@@ -45,6 +45,19 @@ Place `rubocopfmt.el` somewhere into you `load-path` and require it. For example
 With `rubocopfmt-mode` enabled, Ruby buffer will automatically be formatted with
 RuboCop on save.
 
+### Unsafe Cops
+
+RuboCop no longer runs auto-corrections for unsafe cops. To enable unsafe cops,
+set `rubocopfmt-include-unsafe-cops` to `t`. If you're using use-package:
+
+```elisp
+(use-package rubocopfmt
+  :hook
+  (ruby-mode . rubocopfmt-mode)
+  :custom
+  (rubocopfmt-include-unsafe-cops t))
+```
+
 ## Commands
 
 - `rubocopfmt` - Format current buffer with RuboCop.

rubocopfmt.el

@@ -69,7 +69,7 @@
     "Lint/UnusedMethodArgument"  ; Don't rename unused method arguments.
     "Style/EmptyMethod"          ; Don't remove blank line in empty methods.
     )
-  "A list of RuboCop cops to disable during auto-correction.
+  "List of RuboCop cops to disable during auto-correction.
 These cops are disabled because they cause confusion during
 interactive use within a text-editor."
   :type '(repeat string)
@@ -89,6 +89,12 @@ inside a `before-save-hook'."
           (const :tag "None" nil))
   :group 'rubocopfmt)
 
+(defcustom rubocopfmt-include-unsafe-cops nil
+  "When t include unsafe cops when auto-correcting.
+Determines if --auto-correct or --auto-correct-all will be passed to rubocop."
+  :type 'boolean
+  :group 'rubocopfmt)
+
 (defcustom rubocopfmt-major-modes '(ruby-mode enh-ruby-mode)
   "List of major modes to format on save when rubocopfmt-mode is enabled."
   :type '(repeat symbol)
@@ -245,8 +251,10 @@ If FILE is not found in DIRECTORY, the parent of DIRECTORY will be searched."
          (src-dir (file-name-directory buffer-file))
          (src-file (file-name-nondirectory buffer-file))
          (fmt-command rubocopfmt-rubocop-command)
+         (auto-correct-flag (if rubocopfmt-include-unsafe-cops
+                                "--auto-correct-all" "--auto-correct"))
          (fmt-args (list "--stdin" src-file
-                         "--auto-correct"
+                         auto-correct-flag
                          "--format" "emacs")))
 
     (if (and rubocopfmt-use-bundler-when-possible