Add graphql dependency

.travis.yml

@@ -21,10 +21,14 @@ jobs:
       env: DB=MYSQL RECIPE_VERSION=4.x-dev PHPUNIT_TEST=1 PHPCS_TEST=1 PDO=1
     - php: 7.2
       env: DB=PGSQL RECIPE_VERSION=4.x-dev PHPUNIT_COVERAGE_TEST=1
+    - php: 7.2
+      env: DB=PGSQL RECIPE_VERSION=4.x-dev PHPUNIT_COVERAGE_TEST=1 BACKWARD_COMPAT=1
     - php: 7.3
       env: DB=MYSQL RECIPE_VERSION=4.x-dev PHPUNIT_TEST=1
     - php: 7.4
       env: DB=MYSQL RECIPE_VERSION=4.x-dev PHPUNIT_TEST=1
+    - php: 7.4
+      env: DB=MYSQL RECIPE_VERSION=4.x-dev PHPUNIT_TEST=1 BACKWARD_COMPAT=1
     - php: nightly
       env: DB=MYSQL RECIPE_VERSION=4.x-dev PHPUNIT_TEST=1 COMPOSER_ARG=--ignore-platform-reqs
 
@@ -42,7 +46,7 @@ before_script:
   - composer require --no-update sminnee/phpunit-mock-objects:^3
   -
   ######## Remove once GraphQL 4 is merged #########
-  - composer require silverstripe/admin:"dev-pulls/1/schemageddon as 1.x-dev" silverstripe/asset-admin:"dev-pulls/1/schemageddon as 1.x-dev" silverstripe/versioned-admin:"dev-pulls/1/schemageddon as 1.x-dev" silverstripe/cms:"dev-pulls/4/schemageddon as 4.x-dev" --no-update
+  - composer require silverstripe/admin:"dev-pulls/1/schemageddon as 1.x-dev" silverstripe/asset-admin:"dev-pulls/1/schemageddon as 1.x-dev" silverstripe/versioned-admin:"dev-pulls/1/schemageddon as 1.x-dev" silverstripe/cms:"dev-pulls/4/schemageddon as 4.x-dev" silverstripe/graphql:4.x-dev --no-update
   ##################################################
   - 'if [[ $BACKWARD_COMPAT ]]; then composer require silverstripe/graphql:"dev-pulls/3/schemageddon-compat as 3.x-dev" --no-update; fi'
   - if [[ $DB == PGSQL ]]; then composer require silverstripe/postgresql:^2 --no-update; fi