minor #1024 Travis ci (Mazarini)

This PR was squashed before being merged into the master branch (closes #1024).

Discussion
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Travis ci

1) Suppress a "composer install" in .travis.yml
No more need "composer install" + "composer update" since composer 1.9.

2) Update "composer.lock" to use new doctrine/annotation and solve "console cache:clear"  problem with php 7.4.

Commits
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68d5226 Travis ci

Author: javiereguiluz

.travis.yml

@@ -41,8 +41,6 @@ before_install:
   - composer self-update
   # Set memory to max (memory fail)
   - '[[ "$ACTION" == "install" ]] || echo "memory_limit=-1" >> ~/.phpenv/versions/$(phpenv version-name)/etc/conf.d/travis.ini'
-  # Install before update because of memory usage
-  - '[[ "$ACTION" == "install" ]] || composer install'
   # Set stability to dev to allow 4.4dev and 5.0dev
   - '[[ "$ACTION" == "install" ]] || composer config minimum-stability dev'
   # Change version of symfony when need