Removed 7.7 .ci job in favor of 7.8

Author: ezimuel

.ci/jobs/elastic+elasticsearch-php+7.7.yml renamed to .ci/jobs/elastic+elasticsearch-php+7.8.yml

@@ -1,12 +1,12 @@
 ---
 - job:
-    name: elastic+elasticsearch-php+7.7
-    display-name: 'elastic / elasticsearch-php # 7.7'
-    description: Testing the elasticsearch-php 7.7 branch.
+    name: elastic+elasticsearch-php+7.8
+    display-name: 'elastic / elasticsearch-php # 7.8'
+    description: Testing the elasticsearch-php 7.8 branch.
     parameters:
     - string:
         name: branch_specifier
-        default: refs/heads/7.7
+        default: refs/heads/7.8
         description: the Git branch specifier to build (<branchName>, <tagName>,
           <commitId>, etc.)
     triggers: