add license headers to .toml files (#122)

we added .toml to scancode config as part of runtime-rust release; now
we need to add the license headers to the .toml files here.
diff --git a/examples/golang-hello-vendor/src/hello/Gopkg.toml b/examples/golang-hello-vendor/src/hello/Gopkg.toml
index 160eb0e..3fc5f20 100644
--- a/examples/golang-hello-vendor/src/hello/Gopkg.toml
+++ b/examples/golang-hello-vendor/src/hello/Gopkg.toml
@@ -1,3 +1,20 @@
+#
+# 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.
+#
+
 # Gopkg.toml example
 #
 # Refer to https://golang.github.io/dep/docs/Gopkg.toml.html
diff --git a/examples/golang-main-vendor/src/main/Gopkg.toml b/examples/golang-main-vendor/src/main/Gopkg.toml
index d080275..48e74a1 100644
--- a/examples/golang-main-vendor/src/main/Gopkg.toml
+++ b/examples/golang-main-vendor/src/main/Gopkg.toml
@@ -1,3 +1,20 @@
+#
+# 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.
+#
+
 # Gopkg.toml example
 #
 # Refer to https://golang.github.io/dep/docs/Gopkg.toml.html