Summary:
Some files have crept into the repo with the old license header. These are usually from PRs that were opened prior to the re-licensing of the project.
Let the script run, prior to fixing the errant files. The script outputs the following:
```
PATENTS crept into some new files?
--- /dev/fd/63 2018-03-01 01:42:48.250153746 +0000
+++ /dev/fd/62 2018-03-01 01:42:48.250153746 +0000
@@ -1 +1,9 @@
+Libraries/NativeAnimation/Nodes/RCTTrackingAnimatedNode.h
+Libraries/NativeAnimation/Nodes/RCTTrackingAnimatedNode.m
+ReactAndroid/src/main/java/com/facebook/react/animated/TrackingAnimatedNode.java
+ReactAndroid/src/main/java/com/facebook/react/views/text/CustomLetterSpacingSpan.java
+ReactCommon/yoga/yoga/YGLayout.cpp
+ReactCommon/yoga/yoga/YGLayout.h
+ReactCommon/yoga/yoga/YGStyle.cpp
+ReactCommon/yoga/yoga/YGStyle.h
scripts/circleci/check_license.sh
Exited with code 1
```
Fix the headers in these files and run the script again. No output, exit code 0.
Closes https://github.com/facebook/react-native/pull/18143
Reviewed By: sophiebits
Differential Revision: D7119356
Pulled By: hramos
fbshipit-source-id: d238e4d4a3ae320a2c8e625c2fa29690057a4814