Update osx php version and ignore strange pecl install segfault.

Switch to php 7.3 because brew removed 7.1 support.
Switch to xdebug 2.7.2 because no php 7.3 support.

.travis.yml

@@ -2,14 +2,14 @@ language: php
 
 php:
   - '5.6'
-  - '7.1'
+  - '7.3'
 env:
   global:
     - NODE_VERSION=8.9.3
     - NPM_VERSION=^6.3.0
     - BUILD_LEADER_ID=4
   matrix:
-    - XDEBUG_VERSION=2.5.5
+    - XDEBUG_VERSION=2.7.2
 
 sudo: false
 
@@ -18,7 +18,7 @@ cache:
     - $HOME/.npm
 
 before_install:
-  - pecl install xdebug-$XDEBUG_VERSION
+  - pecl install xdebug-$XDEBUG_VERSION || true
   - phpenv config-add travis-php.ini
   - nvm install $NODE_VERSION
   - nvm use $NODE_VERSION
@@ -45,16 +45,16 @@ jobs:
       before_install:
         # Fix ruby error https://github.com/Homebrew/brew/issues/3299
         - brew update
-        - brew install php@7.1
-        - brew link --force --overwrite php@7.1
-        - mkdir -p /usr/local/etc/php/7.1/conf.d
-        - cp travis-php.ini /usr/local/etc/php/7.1/conf.d/
+        - brew install php@7.3
+        - brew link --force --overwrite php@7.3
+        - mkdir -p /usr/local/etc/php/7.3/conf.d
+        - cp travis-php.ini /usr/local/etc/php/7.3/conf.d/
         # see per https://javorszky.co.uk/2018/05/03/getting-xdebug-working-on-php-7-2-and-homebrew/
         # avoid problems with brew's symlink and pecl's recursive mkdir
-        - rm /usr/local/Cellar/php@7.1/7.1.26/pecl
+        - rm /usr/local/Cellar/php@7.3/7.3.12/pecl
         - pecl install xdebug-$XDEBUG_VERSION
         # make xdebug.so available at pecl's expected location
-        - ln -s /usr/local/Cellar/php@7.1/7.1.26/pecl/ /usr/local/lib/php/pecl
+        - ln -s /usr/local/Cellar/php@7.3/7.3.12/pecl/ /usr/local/lib/php/pecl
         - php -i
         - source ~/.nvm/nvm.sh
         - nvm install $NODE_VERSION