[FLINK-27353] Update to Flink 1.15
-rw-r--r-- 84 .asf.yaml
-rw-r--r-- 41 .git-blame-ignore-revs
-rw-r--r-- 435 .gitignore
-rw-r--r-- 16 .scalafmt.conf
-rw-r--r-- 420 .travis.yml
-rw-r--r-- 5486 CONTRIBUTING.md
-rw-r--r-- 11357 LICENSE
-rw-r--r-- 11472 README.md
-rw-r--r-- 11374 README_zh.md
-rw-r--r-- 12400 build.gradle
drwxr-xr-x - common
drwxr-xr-x - config
-rw-r--r-- 151 gradle.properties
drwxr-xr-x - gradle
-rwxr-xr-x 5764 gradlew
-rw-r--r-- 3056 gradlew.bat
drwxr-xr-x - hourly-tips
drwxr-xr-x - long-ride-alerts
drwxr-xr-x - ride-cleansing
drwxr-xr-x - rides-and-fares
-rw-r--r-- 1699 settings.gradle