linter 0.1.59


* relaxed `void_checks` (allowing `T Function()` to be assigned to `void Function()`)
* test and build improvements
* introduced Effective Dart rule set
* Google ruleset updates
* (internal cleanup): move cli main into `lib/`
* fixed false positives in `lines_longer_than_80_chars`
* new lint: `prefer_void_to_null`

Change-Id: I374197f09701041fd0b507062a3ad903f731656a
Reviewed-on: https://dart-review.googlesource.com/69382
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>
Commit-Queue: Phil Quitslund <pquitslund@google.com>
diff --git a/DEPS b/DEPS
index 1d51a0d..79fbdd1 100644
--- a/DEPS
+++ b/DEPS
@@ -95,7 +95,7 @@
   "intl_tag": "0.15.6",
   "jinja2_rev": "2222b31554f03e62600cd7e383376a7c187967a1",
   "json_rpc_2_tag": "2.0.9",
-  "linter_tag": "0.1.58",
+  "linter_tag": "0.1.59",
   "logging_tag": "0.11.3+2",
   "markdown_tag": "2.0.2",
   "matcher_tag": "0.12.3",