[epiphany] Revert "Use own docker image for check-code-style"

[Michael Catanzaro <mcatanzaro src gnome org>]

commit 32877aebd06d6620f062feccec56b1c66a824eb4
Author: Michael Catanzaro <mcatanzaro gnome org>
Date:   Wed Jul 29 18:51:41 2020 +0000

    Revert "Use own docker image for check-code-style"
    
    This reverts commit 0622fb282c0b008980ab72172dbdfe38bde3431e

 .gitlab-ci.yml           |  4 +++-
 .gitlab-ci/Dockerfile    | 14 --------------
 .gitlab-ci/README.md     | 23 -----------------------
 .gitlab-ci/run-docker.sh | 18 ------------------
 4 files changed, 3 insertions(+), 56 deletions(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index b52f6d8f1..c83d7b23a 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -12,8 +12,10 @@ stages:
 
 check-code-style:
   stage: .pre
-  image: registry.gitlab.gnome.org/gnome/epiphany/master:v1
+  image: alpine:latest
   interruptible: true
+  before_script:
+    - apk update && apk add uncrustify bash python3
   script:
     - bash data/check-code-style