minor #15598 moved PHP nightly to PHP 7.0 (fabpot)

This PR was merged into the 2.3 branch.

Discussion
----------

moved PHP nightly to PHP 7.0

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | n/a
| License       | MIT
| Doc PR        | n/a

Commits
-------

40e3ab0 moved PHP nightly to PHP 7.0

.travis.yml

@@ -18,7 +18,7 @@ matrix:
           env: deps=low
         - php: 5.6
           env: deps=high
-        - php: nightly
+        - php: 7.0
     fast_finish: true
 
 services: mongodb
@@ -31,11 +31,11 @@ env:
 before_install:
     - composer self-update
     - if [[ "$TRAVIS_PHP_VERSION" != "hhvm" ]]; then echo "memory_limit = -1" >> ~/.phpenv/versions/$(phpenv version-name)/etc/conf.d/travis.ini; fi;
-    - if [[ "$TRAVIS_PHP_VERSION" != "nightly" ]] && [[ "$TRAVIS_PHP_VERSION" != "hhvm" ]]; then phpenv config-rm xdebug.ini; fi;
-    - if [[ "$TRAVIS_PHP_VERSION" != "nightly" ]] && [[ "$TRAVIS_PHP_VERSION" != "hhvm" ]]; then echo "extension = mongo.so" >> ~/.phpenv/versions/$(phpenv version-name)/etc/php.ini; fi;
-    - if [[ "$TRAVIS_PHP_VERSION" != "nightly" ]] && [[ "$TRAVIS_PHP_VERSION" != "hhvm" ]] && [ $(php -r "echo PHP_MINOR_VERSION;") -le 4 ]; then echo "extension = apc.so" >> ~/.phpenv/versions/$(phpenv version-name)/etc/php.ini; fi;
-    - if [[ "$TRAVIS_PHP_VERSION" != "nightly" ]] && [[ "$TRAVIS_PHP_VERSION" != "hhvm" ]]; then (pecl install -f memcached-2.1.0 && echo "extension = memcache.so" >> ~/.phpenv/versions/$(phpenv version-name)/etc/php.ini) || echo "Let's continue without memcache extension"; fi;
-    - if [[ "$TRAVIS_PHP_VERSION" != "nightly" ]] && [[ "$TRAVIS_PHP_VERSION" != "hhvm" ]]; then php -i; fi;
+    - if [[ "$TRAVIS_PHP_VERSION" != "7.0" ]] && [[ "$TRAVIS_PHP_VERSION" != "hhvm" ]]; then phpenv config-rm xdebug.ini; fi;
+    - if [[ "$TRAVIS_PHP_VERSION" != "7.0" ]] && [[ "$TRAVIS_PHP_VERSION" != "hhvm" ]]; then echo "extension = mongo.so" >> ~/.phpenv/versions/$(phpenv version-name)/etc/php.ini; fi;
+    - if [[ "$TRAVIS_PHP_VERSION" != "7.0" ]] && [[ "$TRAVIS_PHP_VERSION" != "hhvm" ]] && [ $(php -r "echo PHP_MINOR_VERSION;") -le 4 ]; then echo "extension = apc.so" >> ~/.phpenv/versions/$(phpenv version-name)/etc/php.ini; fi;
+    - if [[ "$TRAVIS_PHP_VERSION" != "7.0" ]] && [[ "$TRAVIS_PHP_VERSION" != "hhvm" ]]; then (pecl install -f memcached-2.1.0 && echo "extension = memcache.so" >> ~/.phpenv/versions/$(phpenv version-name)/etc/php.ini) || echo "Let's continue without memcache extension"; fi;
+    - if [[ "$TRAVIS_PHP_VERSION" != "7.0" ]] && [[ "$TRAVIS_PHP_VERSION" != "hhvm" ]]; then php -i; fi;
     # Build a standalone phpunit without symfony/yaml and that works around https://github.com/sebastianbergmann/phpunit-mock-objects/issues/223
     - (mkdir phpunit && cd phpunit && wget https://github.com/sebastianbergmann/phpunit/archive/4.7.zip && unzip 4.7.zip && cd phpunit-4.7 && composer remove --no-update symfony/yaml && composer require --prefer-source phpunit/phpunit-mock-objects '2.3.0')
     - export PHPUNIT="$(readlink -f ./phpunit/phpunit-4.7/phpunit) --colors=always"