test(travis): use Rails 6-1-stable branch, JRuby 9.2.14.0

Author: dr-itz

.travis.yml

@@ -15,7 +15,7 @@ install:
 
 language: ruby
 rvm:
-  - jruby-9.2.13.0
+  - jruby-9.2.14.0
 jdk:
   - openjdk8
 
@@ -111,18 +111,18 @@ matrix:
       env: DB=mariadb PREPARED_STATEMENTS=true
 
     # Rails test-suite :
-    - env: DB=mysql2     TEST_PREFIX="rails:" AR_VERSION="master" # PS off by default
-    - env: DB=mysql2     TEST_PREFIX="rails:" AR_VERSION="master" PREPARED_STATEMENTS=true
-    - env: DB=mysql2     TEST_PREFIX="rails:" AR_VERSION="master" DRIVER=MariaDB
+    - env: DB=mysql2     TEST_PREFIX="rails:" AR_VERSION="6-1-stable" # PS off by default
+    - env: DB=mysql2     TEST_PREFIX="rails:" AR_VERSION="6-1-stable" PREPARED_STATEMENTS=true
+    - env: DB=mysql2     TEST_PREFIX="rails:" AR_VERSION="6-1-stable" DRIVER=MariaDB
 
     - addons:
         postgresql: "10"
-      env: DB=postgresql TEST_PREFIX="rails:" AR_VERSION="master" # PS on by default
+      env: DB=postgresql TEST_PREFIX="rails:" AR_VERSION="6-1-stable" # PS on by default
     - addons:
         postgresql: "10"
-      env: DB=postgresql TEST_PREFIX="rails:" AR_VERSION="master" PREPARED_STATEMENTS=false
+      env: DB=postgresql TEST_PREFIX="rails:" AR_VERSION="6-1-stable" PREPARED_STATEMENTS=false
     - addons:
         postgresql: "9.4"
-      env: DB=postgresql TEST_PREFIX="rails:" AR_VERSION="master" # PS on by default
+      env: DB=postgresql TEST_PREFIX="rails:" AR_VERSION="6-1-stable" # PS on by default
 
-    - env: DB=sqlite3    TEST_PREFIX="rails:" AR_VERSION="master"
+    - env: DB=sqlite3    TEST_PREFIX="rails:" AR_VERSION="6-1-stable"