Update travis.

Signed-off-by: Mior Muhammad Zaki <crynobone@gmail.com>

.travis.yml

@@ -5,6 +5,8 @@ sudo: false
 php:
   - 7.1
   - 7.2
+  - 7.3
+  - nightly
 
 env:
   global:
@@ -19,10 +21,10 @@ before_install:
   - composer config discard-changes true
 
 before_script:
-  - if [[ $setup = 'basic' ]]; then travis_retry composer install --prefer-dist --no-interaction; fi
-  - if [[ $setup = 'stable' ]]; then travis_retry composer update --prefer-dist --no-interaction --prefer-stable; fi
-  - if [[ $setup = 'lowest' ]]; then travis_retry composer update --prefer-dist --no-interaction --prefer-lowest --prefer-stable; fi
-  - if [[ $setup = 'coveralls' ]]; then travis_retry composer require "php-coveralls/php-coveralls=^2.1" --prefer-dist --no-interaction --dev; fi
+  - if [[ $setup = 'basic' ]]; then travis_retry composer install --prefer-dist --no-interaction --no-suggest; fi
+  - if [[ $setup = 'stable' ]]; then travis_retry composer update --prefer-dist --no-interaction --no-suggest --prefer-stable; fi
+  - if [[ $setup = 'lowest' ]]; then travis_retry composer update --prefer-dist --no-interaction --no-suggest --prefer-lowest --prefer-stable; fi
+  - if [[ $setup = 'coveralls' ]]; then travis_retry composer require "php-coveralls/php-coveralls=^2.1" --prefer-dist --no-interaction --no-suggest --dev; fi
 
 script:
   - if [[ $coverage = 'yes' ]]; then ./vendor/bin/phpunit -c phpunit.xml --coverage-clover build/logs/clover.xml; fi
@@ -36,5 +38,6 @@ matrix:
     - php: 7.1
       env: setup=coveralls coverage=yes
   allow_failures:
+    - php: nightly
     - env: setup=coveralls coverage=yes
   fast_finish: true