Go back to working build

.travis.yml

@@ -1,18 +1,13 @@
 dist: xenial
 os: linux
 
-arch:
-  - amd64
-  - arm64
-  - ppc64le
+arch: amd64
 
 language: php
 
 services:
-  - if: arch = amd64
-    - [ mysql, postgresql ]
-  - if: arch != amd64
   - mysql
+  - postgresql
 
 php:
   - 7.2
@@ -21,7 +16,6 @@ php:
   - nightly
 
 before_script:
-  - if: arch = amd64
   - psql -c 'DROP DATABASE IF EXISTS test;' -U postgres
   - psql -c 'create database test;' -U postgres
   - mysql -e 'create database IF NOT EXISTS test;'
@@ -40,4 +34,3 @@ after_script:
 jobs:
   allow_failures:
     - php: nightly
-    - arch: [arm64, ppc64le]