Add DCO and remove Microsoft CLA section (#686)

Signed-off-by: Zbynek Roubalik <zroubali@redhat.com>

CONTRIBUTING.md

@@ -26,10 +26,33 @@ For any contribution you make that impacts the behavior or experience of KEDA, p
 
 [Details on setup of a development environment are found on the README](https://github.com/kedacore/keda#building-quick-start-with-visual-studio-code-remote---containers)
 
-## Contributor License Agreement (CLA) and Code of Conduct
+## Developer Certificate of Origin: Signing your work
 
-Most contributions require you to agree to a Contributor License Agreement (CLA) declaring that you have the right to, and actually do, grant us the rights to use your contribution. For details, visit https://cla.microsoft.com.
+**Every commit needs to be signed.**
 
-When you submit a pull request, a CLA-bot will automatically determine whether you need to provide a CLA and decorate the PR appropriately (e.g., label, comment). Simply follow the instructions provided by the bot. You will only need to do this once across all repos using our CLA.
+The Developer Certificate of Origin (DCO) is a lightweight way for contributors to certify that they wrote or otherwise have the right to submit the code they are contributing to the project. Here is the full text of the DCO, reformatted for readability:
+```
+By making a contribution to this project, I certify that:
 
-This project has adopted the Microsoft Open Source Code of Conduct. For more information see the Code of Conduct FAQ or contact opencode@microsoft.com with any additional questions or comments.
+    (a) The contribution was created in whole or in part by me and I have the right to submit it under the open source license indicated in the file; or
+
+    (b) The contribution is based upon previous work that, to the best of my knowledge, is covered under an appropriate open source license and I have the right under that license to submit that work with modifications, whether created in whole or in part by me, under the same open source license (unless I am permitted to submit under a different license), as indicated in the file; or
+
+    (c) The contribution was provided directly to me by some other person who certified (a), (b) or (c) and I have not modified it.
+
+    (d) I understand and agree that this project and the contribution are public and that a record of the contribution (including all personal information I submit with it, including my sign-off) is maintained indefinitely and may be redistributed consistent with this project or the open source license(s) involved.
+```
+
+Contributors sign-off that they adhere to these requirements by adding a `Signed-off-by` line to commit messages.
+
+```
+This is my commit message
+
+Signed-off-by: Random J Developer <random@developer.example.org>
+```
+Git even has a `-s` command line option to append this automatically to your commit message:
+```
+$ git commit -s -m 'This is my commit message'
+```
+
+Each Pull Request is checked  whether or not commits in a Pull Request do contain a valid Signed-off-by line.

README.md

@@ -41,6 +41,10 @@ You can find several samples for various event sources [here](https://github.com
 
 You can find the latest releases [here](https://github.com/kedacore/keda/releases)
 
+## Contributing
+
+You can find Contributing guide [here](./CONTRIBUTING.md)
+
 ## Community
 
 If interested in contributing or participating in the direction of KEDA, you can join our community meetings.
@@ -175,18 +179,3 @@ Find `--v=0` argument in Operator Deployment section in `deploy/22-metrics-deplo
 Allowed values are `"0"` for info, `"4"` for debug, or an integer value greater than `0`, specified as string
 
 Default value: `"0"`
-
-
-# Contributing
-
-This project welcomes contributions and suggestions. Most contributions require you to agree to a
-Contributor License Agreement (CLA) declaring that you have the right to, and actually do, grant us
-the rights to use your contribution. For details, visit https://cla.microsoft.com.
-
-When you submit a pull request, a CLA-bot will automatically determine whether you need to provide
-a CLA and decorate the PR appropriately (e.g., label, comment). Simply follow the instructions
-provided by the bot. You will only need to do this once across all repos using our CLA.
-
-This project has adopted the [Microsoft Open Source Code of Conduct](https://opensource.microsoft.com/codeofconduct/).
-For more information see the [Code of Conduct FAQ](https://opensource.microsoft.com/codeofconduct/faq/) or
-contact [opencode@microsoft.com](mailto:opencode@microsoft.com) with any additional questions or comments.