[nongnu] elpa/pdf-tools 007fcf1fe9: Add Emacs 28 to CircleCI build matrix

[ELPA Syncer]

branch: elpa/pdf-tools
commit 007fcf1fe9f8d74bcf7a88581b724b0f15022243
Author: Piotr Kwiecinski <piotr.kwiecinski@codemanufacture.com>
Commit: Vedang Manerikar <ved.manerikar@gmail.com>

    Add Emacs 28 to CircleCI build matrix
---
 .circleci/config.yml | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/.circleci/config.yml b/.circleci/config.yml
index 1f143fc17d..082583b33d 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -31,6 +31,12 @@ jobs:
         entrypoint: bash
     <<: *default-steps
 
+  test-emacs-28:
+    docker:
+      - image: silex/emacs:28-ci-cask
+        entrypoint: bash
+    <<: *default-steps
+
   test-emacs-master:
     docker:
       - image: silex/emacs:master-ci-cask
@@ -44,4 +50,5 @@ workflows:
       - test-emacs-25
       - test-emacs-26
       - test-emacs-27
+      - test-emacs-28
       - test-emacs-master