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/consolidation/output-formatters/.travis.yml

@@ -6,11 +6,20 @@ branches:
     - master
     - /^[[:digit:]]+\.[[:digit:]]+\.[[:digit:]]+.*$/
 
-php:
-  - 7.0
-  - 5.6
-  - 5.5
-  - 5.4
+matrix:
+  include:
+    -
+      php: 7.1
+      env: 'HIGHEST_LOWEST="update" STABILITY="RC"'
+    -
+      php: 7.0.11
+    -
+      php: 5.6
+    -
+      php: 5.5
+    -
+      php: 5.4
+      env: 'HIGHEST_LOWEST="update --prefer-lowest"'
 
 sudo: false
 
@@ -20,7 +29,17 @@ cache:
     - $HOME/.composer/cache
 
 before_script:
-  - composer install
+  # If running a highest/lowest dependencies test, get rid of composer.lock
+  - |
+    if [ -n "$HIGHEST_LOWEST" ] ; then
+      rm composer.lock
+      composer config --unset platform.php
+      composer config minimum-stability ${STABILITY-stable}
+    fi
+  - 'composer -n ${HIGHEST_LOWEST-install} --prefer-dist'
+  - composer why symfony/console
+  # Print out all  of the installed packages in alphabetical order, with versions
+  - composer licenses
 
 script:
   - vendor/bin/phpunit