Actualizar 3.1.5 a 3.2.3 Errores

Tengo una duda es posible actualizar pilaga 3.1.5 a 3.2.3? es necesario actualizar php? yo en el mismo entorno tengo funcionando pilaga diaguita, toba , arai proveedores. Todas estas versiones trabajaran con php 7> ?

Gracias

Aca paso el resultado de los comando:

root@pilaga:/var/www/SIU-Pilaga_3.2.3# ./bin/instalador proyecto:actualizar --instalacion-anterior /var/www/siu/
Error, no se ejecuto el comando ‘composer install’
root@pilaga:/var/www/SIU-Pilaga_3.2.3# composer install
Loading composer repositories with package information
Installing dependencies (including require-dev) from lock file
Your requirements could not be resolved to an installable set of packages.

Problem 1
- Installation request for siu/api-afip v1.0.0 → satisfiable by siu/api-afip[v1.0.0].
- siu/api-afip v1.0.0 requires ext-soap * → the requested PHP extension soap is missing from your system.
Problem 2
- Installation request for symfony/config v4.1.6 → satisfiable by symfony/config[v4.1.6].
- symfony/config v4.1.6 requires php ^7.1.3 → your PHP version (5.6.38) does not satisfy that requirement.
Problem 3
- Installation request for myclabs/deep-copy 1.8.1 → satisfiable by myclabs/deep-copy[1.8.1].
- myclabs/deep-copy 1.8.1 requires php ^7.1 → your PHP version (5.6.38) does not satisfy that requirement.
Problem 4
- Installation request for phpdocumentor/reflection-docblock 4.3.0 → satisfiable by phpdocumentor/reflection-docblock[4.3.0].
- phpdocumentor/reflection-docblock 4.3.0 requires php ^7.0 → your PHP version (5.6.38) does not satisfy that requirement.
Problem 5
- Installation request for phpunit/php-token-stream 2.0.2 → satisfiable by phpunit/php-token-stream[2.0.2].
- phpunit/php-token-stream 2.0.2 requires php ^7.0 → your PHP version (5.6.38) does not satisfy that requirement.
Problem 6
- symfony/config v4.1.6 requires php ^7.1.3 → your PHP version (5.6.38) does not satisfy that requirement.
- robmorgan/phinx 0.10.6 requires symfony/config ^2.8|^3.0|^4.0 → satisfiable by symfony/config[v4.1.6].
- Installation request for robmorgan/phinx 0.10.6 → satisfiable by robmorgan/phinx[0.10.6].

To enable extensions, verify that they are enabled in those .ini files:
- /etc/php/5.6/cli/php.ini
- /etc/php/5.6/cli/conf.d/10-opcache.ini
- /etc/php/5.6/cli/conf.d/10-pdo.ini
- /etc/php/5.6/cli/conf.d/15-xml.ini
- /etc/php/5.6/cli/conf.d/20-calendar.ini
- /etc/php/5.6/cli/conf.d/20-ctype.ini
- /etc/php/5.6/cli/conf.d/20-curl.ini
- /etc/php/5.6/cli/conf.d/20-dom.ini
- /etc/php/5.6/cli/conf.d/20-exif.ini
- /etc/php/5.6/cli/conf.d/20-fileinfo.ini
- /etc/php/5.6/cli/conf.d/20-ftp.ini
- /etc/php/5.6/cli/conf.d/20-gd.ini
- /etc/php/5.6/cli/conf.d/20-gettext.ini
- /etc/php/5.6/cli/conf.d/20-iconv.ini
- /etc/php/5.6/cli/conf.d/20-json.ini
- /etc/php/5.6/cli/conf.d/20-mbstring.ini
- /etc/php/5.6/cli/conf.d/20-mcrypt.ini
- /etc/php/5.6/cli/conf.d/20-pdo_pgsql.ini
- /etc/php/5.6/cli/conf.d/20-pgsql.ini
- /etc/php/5.6/cli/conf.d/20-phar.ini
- /etc/php/5.6/cli/conf.d/20-posix.ini
- /etc/php/5.6/cli/conf.d/20-readline.ini
- /etc/php/5.6/cli/conf.d/20-shmop.ini
- /etc/php/5.6/cli/conf.d/20-simplexml.ini
- /etc/php/5.6/cli/conf.d/20-sockets.ini
- /etc/php/5.6/cli/conf.d/20-sysvmsg.ini
- /etc/php/5.6/cli/conf.d/20-sysvsem.ini
- /etc/php/5.6/cli/conf.d/20-sysvshm.ini
- /etc/php/5.6/cli/conf.d/20-tokenizer.ini
- /etc/php/5.6/cli/conf.d/20-wddx.ini
- /etc/php/5.6/cli/conf.d/20-xmlreader.ini
- /etc/php/5.6/cli/conf.d/20-xmlwriter.ini
- /etc/php/5.6/cli/conf.d/20-xsl.ini
- /etc/php/5.6/cli/conf.d/20-zip.ini
You can also run php --ini inside terminal to see which files are used by PHP in CLI mode.

Hola, no hay inconveniente para actualizar el php a 7.1 ya que SIU-Diaguita 2.5 y SIU-Pilaga 3.2.3 funcionan sin problema.
Saludos
Mariana