Update Travis to test with 1.3.3 driver

.travis.yml

@@ -14,7 +14,7 @@ matrix:
   fast_finish: true
   include:
     - php: 5.5
-      env: &common_env DRIVER_VERSION=1.3.0RC1 SERVER_VERSION=3.4
+      env: &common_env DRIVER_VERSION=1.3.3 SERVER_VERSION=3.4
       addons: &common_addons
         apt: 
           sources: [ mongodb-3.4-precise ]
@@ -32,25 +32,25 @@ matrix:
       env: *common_env
       addons: *common_addons
     - php: 7.0
-      env: DRIVER_VERSION=1.3.0RC1 SERVER_VERSION=2.4
+      env: DRIVER_VERSION=1.3.3 SERVER_VERSION=2.4
       addons:
         apt:
           sources: [ mongodb-upstart ]
           packages: [ mongodb-10gen, *common_packages ]
     - php: 7.0
-      env: DRIVER_VERSION=1.3.0RC1 SERVER_VERSION=2.6
+      env: DRIVER_VERSION=1.3.3 SERVER_VERSION=2.6
       addons:
         apt:
           sources: [ mongodb-upstart ]
           packages: [ mongodb-org, *common_packages ]
     - php: 7.0
-      env: DRIVER_VERSION=1.3.0RC1 SERVER_VERSION=3.0
+      env: DRIVER_VERSION=1.3.3 SERVER_VERSION=3.0
       addons:
         apt:
           sources: [ mongodb-3.0-precise ]
           packages: [ mongodb-org, *common_packages ]
     - php: 7.0
-      env: DRIVER_VERSION=1.3.0RC1 SERVER_VERSION=3.2
+      env: DRIVER_VERSION=1.3.3 SERVER_VERSION=3.2
       addons:
         apt:
           sources: [ mongodb-3.2-precise ]