remove tests for old php versions

Author: cesargb

.travis.yml

@@ -1,8 +1,6 @@
 language: php
 
 php:
-  - 7.0
-  - 7.1
   - 7.2
   - 7.3
 
@@ -11,13 +9,6 @@ env:
     - COMPOSER_FLAGS="--prefer-lowest"
     - COMPOSER_FLAGS=""
 
-matrix:
-  exclude:
-  - php: 7.2
-    env: COMPOSER_FLAGS="--prefer-lowest"
-  - php: 7.3
-    env: COMPOSER_FLAGS="--prefer-lowest"
-
 before_script:
   - travis_retry composer self-update
   - travis_retry composer update ${COMPOSER_FLAGS} --no-interaction --prefer-source