Try installing zookeeper extension.

GaneshChandrasekaran-zz · GaneshChandrasekaran-zz · commit 5726c1f65cc6 · 2018-07-22T13:14:15.000+02:00
diff --git a/.travis.yml b/.travis.yml
@@ -106,14 +106,15 @@ before_install:
           local ext_name=$1
           local ext_so=$2
           local INI=$3
+          local ext_opt=$4
           local ext_dir=$(php -r "echo ini_get('extension_dir');")
           local ext_cache=~/php-ext/$(basename $ext_dir)/$ext_name
 
           if [[ -e $ext_cache/$ext_so ]]; then
               echo extension = $ext_cache/$ext_so >> $INI
           else
               mkdir -p $ext_cache
-              echo yes | pecl install -f $ext_name &&
+              echo yes | pecl install -f $ext_name $etx_opt &&
               cp $ext_dir/$ext_so $ext_cache
           fi
       }
@@ -147,11 +148,16 @@ before_install:
           sudo apt-get update -q
           sudo apt-get install libsodium-dev -y
 
+          # install lib-zookeeper
+          wget http://www-us.apache.org/dist/zookeeper/zookeeper-3.4.12/zookeeper-3.4.12.tar.gz | tar -zxf zookeeper-3.4.12.tar.gz
+
+
           tfold ext.apcu tpecl apcu-5.1.6 apcu.so $INI
           tfold ext.libsodium tpecl libsodium sodium.so $INI
           tfold ext.mongodb tpecl mongodb-1.5.0 mongodb.so $INI
           tfold ext.amqp tpecl amqp-1.9.3 amqp.so $INI
           tfold ext.igbinary tpecl igbinary-2.0.6 igbinary.so $INI
+          tfold ext.zookeeper tpecl zookeeper-0.5.0 zookeeper.so $INI --with-libzookeeper-dir="zookeeper-3.4.12/src/c"
       fi
 
     - |
