How to upgrade magento 2.1.0 to the latest version

Here is an example of how to upgrade magento 2.1.0 to 2.1.5

You can use following steps with composer update:

composer require magento/product-community-edition 2.1.5 --no-update
composer update
rm -rf var/di var/generation
php bin/magento cache:flush
php bin/magento setup:upgrade
php bin/magento setup:di:compile
php bin/magento indexer:reindex
chmod -R 777 var

After upgrade, check your Magento version with the following command:

php bin/magento --version