Configures Travis CI to run unit and integration tests in parallel.

Author: dsposito

.travis.yml

@@ -5,6 +5,11 @@ php:
   - '7.1'
   - nightly
 
+# Configure environment to run test suites in parallel.
+env:
+  - TEST_SUITE = "Unit Tests"
+  - TEST_SUITE = "Integration Tests"
+
 # Install test coverage package.
 install:
   - composer require satooshi/php-coveralls
@@ -17,7 +22,7 @@ before_script:
 
 # Run tests and generate test coverage report.
 script:
-  - phpunit -d api_key=$API_KEY --coverage-clover build/logs/clover.xml
+  - phpunit -d api_key=$API_KEY --testsuite $TEST_SUITE --coverage-clover build/logs/clover.xml
 
 # Submit test coverage report to Coveralls.
 after_success: