Revert "Support license checker (#65)"

This reverts commit d0fa7a3be67712ec6ad28223c6a1855e8c91e22c.
diff --git a/.github/workflows/license_checker.yml b/.github/workflows/license_checker.yml
deleted file mode 100644
index 5735f8b..0000000
--- a/.github/workflows/license_checker.yml
+++ /dev/null
@@ -1,15 +0,0 @@
-name: Check License Lines
-on:
-  pull_request:
-    types: [opened, reopened, synchronize]
-  push:
-    branches:
-      - master
-jobs:
-  check-license-lines:
-    runs-on: ubuntu-latest
-    steps:
-      - name: Checkout
-        uses: actions/checkout@v2
-      - name: Check License Lines
-        uses: kt3k/license_checker@v1.0.6
diff --git a/.licenserc.json b/.licenserc.json
deleted file mode 100644
index 4279a24..0000000
--- a/.licenserc.json
+++ /dev/null
@@ -1,3 +0,0 @@
-{
-    "**/*.java": "/\\*\nLicensed to the Apache Software Foundation*"
-  }
\ No newline at end of file