Update install

Adding support for Debian 9 Stretch

install

@@ -135,7 +135,7 @@ function systemInitDetect() {
     # Get the path of the command where pid=1 following any symlinks
     pid_1_path=$(readlink --canonicalize -n /proc/1/exe)
     # returns '/sbin/init' (Debian Wheezy & Ubuntu Trusty)
-    # returns '(/usr)?/lib/systemd/systemd' (Debian Jessie, Ubuntu Xenial, CentOS 7)
+    # returns '(/usr)?/lib/systemd/systemd' (Debian Stretch, Debian Jessie, Ubuntu Xenial, CentOS 7)
     verbose "Detected path to PID=1 process: $pid_1_path"
     # Get package of PID=1 path as it identifies the init system
     pid_1_package=$(dpkg -S $pid_1_path 2>/dev/null || 
@@ -566,6 +566,7 @@ fi
 
 # Validate the distribution and release is a supported one; set boolean flags.
 is_debian_dist=false
+is_debian_stretch=false
 is_debian_jessie=false
 is_debian_wheezy=false
 is_ubuntu_dist=false
@@ -589,6 +590,11 @@ case "${dist}-${code}" in
         is_ubuntu_dist=true
         is_ubuntu_trusty=true
         ;;
+    debian-9|debian-stretch)
+        code="stretch"
+        is_debian_dist=true
+        is_debian_stretch=true
+        ;;
     debian-8|debian-jessie)
         code="jessie"
         is_debian_dist=true
@@ -641,6 +647,7 @@ if [ "$ignore_dependencies" = "f" ]; then
         apt_force_options="--allow-downgrades --allow-remove-essential --allow-change-held-packages"
         # Get apt-get version by returning the 2nd parameter from the 1st line of output
         apt_version=$(apt-get --version |awk 'NR == 1 { print $2 }')
+        # returns: 1.4.7 (Debian Stretch)
         # returns: 0.9.7.9 (Debian Wheezy)
         # returns: 1.0.1ubuntu2 (Ubuntu Trusty)
         # returns: 1.0.9.8.4 (Debian Jessie)
@@ -939,7 +946,7 @@ loud "-----------------------------------------------------"
 # Test common locations for php conf directory
 php_conf_dirs=(
     "/etc/php/7.0/apache2/conf.d"   # Ubuntu Xenial
-    "/etc/php5/apache2/conf.d"      # Debian Jessie, Ubuntu Trusty
+    "/etc/php5/apache2/conf.d"      # Debian Stretch, Debian Jessie, Ubuntu Trusty
     "/etc/php.d"                    # CentOS 7
 )
 for php_conf in ${php_conf_dirs[@]}; do