Supporting log level for log-requests from configuration

[lambdadbmal]

Add new configuration feature to modify log-requests' log level.

You can modify requests log level in your config like ...

:duct.middleware.web/log-requests {:level :debug}

Also you can hide all requests log like ...

:duct.middleware.web/log-requests {:level :debug}
:duct.logger/timbre {:level :info}

[weavejester]

Also, can you change the commit message to:

Add support for changing log level of requests

[lambdadbmal]

Thank you for reviewing again. I fixed all of you mentioned.

[lambdadbmal]

Thank you. I fixed codes as you mentioned. I also squashed all of commits.

[lambdadbmal]

Hi, how's it going? I would think you are still busy. If you have a time to continue handling this PR, please let me know. Take it easy.

[weavejester]

Thanks again for your work on this. Sorry it took so long to merge.

[lambdadbmal]

Thank you for merging my PR.