Add pear modules, mail and net_smtp via composer (#93)

Add pear modules, mail and net_smtp via composer, remove php 5.6 build due to phpunit 6

lib/composer/vendor/sebastian/recursion-context/.travis.yml

@@ -1,21 +1,23 @@
 language: php
 
 php:
-  - 5.3.3
-  - 5.3
-  - 5.4
-  - 5.5
-  - 5.6
-  - hhvm
+  - 7.0
+  - 7.0snapshot
+  - 7.1
+  - 7.1snapshot
+  - master
 
 sudo: false
 
-before_script:
+before_install:
   - composer self-update
-  - composer install --no-interaction --prefer-source --dev
+  - composer clear-cache
 
-script: ./vendor/bin/phpunit
+install:
+  - travis_retry composer update --no-interaction --no-ansi --no-progress --no-suggest --optimize-autoloader --prefer-stable
+
+script:
+  - ./vendor/bin/phpunit
 
 notifications:
   email: false
-  irc: "irc.freenode.org#phpunit"