Merge ~cjwatson/launchpad:pre-commit-eslint into launchpad:master

[Colin Watson]

Enforce eslint in pre-commit

[Ioana Lasc (ilasc)]

review: Approve

diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index f0e3a44..e6f8850 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -30,3 +30,8 @@ repos:
     rev: 5.9.2
     hooks:
     -   id: isort
+-   repo: https://github.com/pre-commit/mirrors-eslint
+    rev: v4.2.0
+    hooks:
+    -   id: eslint
+        args: [--quiet]