Update Conan server to Artifactory migration script

[danimtb]

Hi colleagues!

Here you have an update of the Conan server to Artifactory migration script. It has been tested with Python 2.7 and Python 3.7

Tasks done:

• Update Conan search command to use wildcard
• Decode strings into UTF-8 to avoid byte strings
• Use format for strings

Hopefully, it will be helpful for new users onboarding Artifactory. Cheers!