Escape regex for PCRE2 compatibility (#81)

Test against PHP 7.3
Use composer memory limit as env variable for php 5.6

Author: lunetics

.travis.yml

@@ -34,30 +34,33 @@ matrix:
     fast_finish: true
     include:
           # Minimum supported Symfony version and latest PHP version
-        - php: 7.2
+        - php: 7.3
           env: COMPOSER_FLAGS="--prefer-stable --prefer-lowest" SYMFONY_DEPRECATIONS_HELPER="weak"
         - php: 5.6
-          env: COMPOSER_FLAGS="--prefer-stable --prefer-lowest" SYMFONY_DEPRECATIONS_HELPER="weak"
+          env: COMPOSER_MEMORY_LIMIT=-1 COMPOSER_FLAGS="--prefer-stable --prefer-lowest" SYMFONY_DEPRECATIONS_HELPER="weak"
 
           # Test the latest stable release
         - php: 5.6
+          env: COMPOSER_MEMORY_LIMIT=-1
         - php: 7.0
           env: SYMFONY_PHPUNIT_VERSION="6.3"
         - php: 7.1
           env: SYMFONY_PHPUNIT_VERSION="6.3"
+        - php: 7.2
+          env: COVERAGE=true TEST_COMMAND="composer test-ci"
         - php: 7.2
           env: COVERAGE=true TEST_COMMAND="composer test-ci"
 
           # Test LTS versions
-        - php: 7.2
+        - php: 7.3
           env: DEPENDENCIES="dunglas/symfony-lock:^2"
-        - php: 7.2
+        - php: 7.3
           env: DEPENDENCIES="dunglas/symfony-lock:^3"
-        - php: 7.2
+        - php: 7.3
           env: DEPENDENCIES="dunglas/symfony-lock:^4"
 
           # Latest commit to master
-        - php: 7.2
+        - php: 7.3
           env: STABILITY="dev"
 
     allow_failures:

.travis/php.ini

@@ -4,4 +4,4 @@ apc.use_request_time=0
 
 extension = memcached.so
 
-
+memory_limit=-1

src/DSN.php

@@ -225,7 +225,7 @@ private function parseDsn($dsn)
 
     private function parseHosts($hostString)
     {
-        preg_match_all('/(?P<host>[\w-._]+)(?::(?P<port>\d+))?/mi', $hostString, $matches);
+        preg_match_all('/(?P<host>[\w\-._]+)(?::(?P<port>\d+))?/mi', $hostString, $matches);
 
         $hosts = [];
         foreach ($matches['host'] as $index => $match) {