Add drone step for postgres with php 7.1

Signed-off-by: Roeland Jago Douma <roeland@famdouma.nl>

.drone.yml

@@ -300,6 +300,15 @@ pipeline:
       matrix:
         DB: postgres
         PHP: "7.0"
+  postgres-php7.1:
+    image: nextcloudci/php7.1:php7.1-15
+    commands:
+      - sleep 10 # gives the database enough time to initialize
+      - NOCOVERAGE=true TEST_SELECTION=DB ./autotest.sh pgsql
+    when:
+      matrix:
+        DB: postgres
+        PHP: 7.1
   mysqlmb4-php5.6:
     image: nextcloudci/php5.6:php5.6-8
     commands:
@@ -722,6 +731,9 @@ matrix:
     - DB: postgres
       PHP: 7.0
       ENABLE_REDIS: true
+    - DB: postgres
+      PHP: 7.1
+      ENABLE_REDIS: true
     - DB: mysqlmb4
       PHP: 5.6
       ENABLE_REDIS: true