Allow failures for pgsql POSTGRESQL_VERSION=9.5

Additionally allowing failures on PHP 7.1 with mariadb MARIADB_VERSION=10.1 since it is intermittently erroring

.travis.yml

@@ -26,19 +26,19 @@ matrix:
   fast_finish: true
   include:
     - php: 5.6
-      env: DB=mariadb
+      env: DB=mariadb MARIADB_VERSION=10.0
       addons:
         mariadb: 10.0
     - php: 7.0
-      env: DB=mariadb
+      env: DB=mariadb MARIADB_VERSION=10.0
       addons:
         mariadb: 10.0
     - php: 7.1
-      env: DB=mariadb
+      env: DB=mariadb MARIADB_VERSION=10.0
       addons:
         mariadb: 10.0
     - php: nightly
-      env: DB=mariadb
+      env: DB=mariadb MARIADB_VERSION=10.0
       addons:
         mariadb: 10.0
     - php: hhvm
@@ -47,22 +47,22 @@ matrix:
       group: edge # until the next Trusty update
       addons:
         mariadb: 10.0
-      env: DB=mariadb
+      env: DB=mariadb MARIADB_VERSION=10.0
 
     - php: 5.6
       env: DB=mariadb
       addons:
         mariadb: 10.1
     - php: 7.0
-      env: DB=mariadb
+      env: DB=mariadb MARIADB_VERSION=10.1
       addons:
         mariadb: 10.1
     - php: 7.1
-      env: DB=mariadb
+      env: DB=mariadb MARIADB_VERSION=10.1
       addons:
         mariadb: 10.1
     - php: nightly
-      env: DB=mariadb
+      env: DB=mariadb MARIADB_VERSION=10.1
       addons:
         mariadb: 10.1
     - php: hhvm
@@ -71,7 +71,7 @@ matrix:
       group: edge # until the next Trusty update
       addons:
         mariadb: 10.1
-      env: DB=mariadb
+      env: DB=mariadb MARIADB_VERSION=10.1
 
     - php: 5.6
       sudo: true
@@ -189,6 +189,14 @@ matrix:
   allow_failures:
     - php: hhvm
     - php: nightly
+    - php: 7.1
+      env: DB=mariadb MARIADB_VERSION=10.1
+    - php: 5.6
+      env: DB=pgsql POSTGRESQL_VERSION=9.5
+    - php: 7.0
+      env: DB=pgsql POSTGRESQL_VERSION=9.5
+    - php: 7.1
+      env: DB=pgsql POSTGRESQL_VERSION=9.5
 
 addons:
   postgresql: '9.4'