Update Dockerfiles to full ASF license header (#137)

diff --git a/tests/dat/docker/nodejs10docker/Dockerfile b/tests/dat/docker/nodejs10docker/Dockerfile
index cab4dbe..2efdd32 100644
--- a/tests/dat/docker/nodejs10docker/Dockerfile
+++ b/tests/dat/docker/nodejs10docker/Dockerfile
@@ -1,3 +1,19 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
 FROM action-nodejs-v10
 COPY package.json .
-RUN npm install --production
\ No newline at end of file
+RUN npm install --production
diff --git a/tests/dat/docker/nodejs12docker/Dockerfile b/tests/dat/docker/nodejs12docker/Dockerfile
index c586748..426097c 100644
--- a/tests/dat/docker/nodejs12docker/Dockerfile
+++ b/tests/dat/docker/nodejs12docker/Dockerfile
@@ -1,3 +1,19 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
 FROM action-nodejs-v12
 COPY package.json .
 RUN npm install --production
diff --git a/tests/dat/docker/nodejs6docker/Dockerfile b/tests/dat/docker/nodejs6docker/Dockerfile
index 63a26e1..a513cc4 100644
--- a/tests/dat/docker/nodejs6docker/Dockerfile
+++ b/tests/dat/docker/nodejs6docker/Dockerfile
@@ -1,3 +1,19 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
 FROM nodejs6action
 COPY package.json .
-RUN npm install --production
\ No newline at end of file
+RUN npm install --production
diff --git a/tests/dat/docker/nodejs8docker/Dockerfile b/tests/dat/docker/nodejs8docker/Dockerfile
index d1f6ada..eb4e3a4 100644
--- a/tests/dat/docker/nodejs8docker/Dockerfile
+++ b/tests/dat/docker/nodejs8docker/Dockerfile
@@ -1,3 +1,19 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
 FROM action-nodejs-v8
 COPY package.json .
-RUN npm install --production
\ No newline at end of file
+RUN npm install --production