Rebase private OTA libs on 2.7

libs/ota-http-client/LICENSE

@@ -0,0 +1,14 @@
+Copyright (c) 2018 Cesanta Software Limited
+All rights reserved
+
+Licensed 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.