Update sqlsrv driver to 4.3.0

Thanks Matteo!

Fixes #6

Author: danpoltawski

root/tmp/setup/php-extensions.sh

@@ -45,7 +45,7 @@ curl https://packages.microsoft.com/config/debian/8/prod.list -o /etc/apt/source
 apt-get update
 ACCEPT_EULA=Y apt-get install -y msodbcsql
 
-pecl install sqlsrv-4.1.6.1
+pecl install sqlsrv-4.3.0
 docker-php-ext-enable sqlsrv
 
 # Keep our image size down..