Fixes #9: Push release version tags automatically, and remove 7.0 from Travis tests.

Author: geerlingguy

.travis.yml

@@ -6,7 +6,6 @@ env:
   - php_version: '7.3'
   - php_version: '7.2'
   - php_version: '7.1'
-  - php_version: '7.0'
   - php_version: '5.6'
 
 install:
@@ -39,6 +38,10 @@ after_success:
       docker tag geerlingguy/php-apache:${php_version} geerlingguy/php-apache:${php_version}.x
       docker push geerlingguy/php-apache:${php_version}.x
 
+      # Push $php_version + '.PHP_RELEASE_VERSION' tag.
+      php_release_version=$(docker run --rm geerlingguy/php-apache:${php_version} bash -c "php -r 'echo PHP_RELEASE_VERSION;'")
+      docker tag geerlingguy/php-apache:${php_version} geerlingguy/php-apache:${php_version}.${php_release_version}
+
       # Push latest tag if building latest version.
       if [[ "$php_version" == "7.3" ]]; then
         docker tag geerlingguy/php-apache:${php_version} geerlingguy/php-apache:latest