Script to generating keys and placing them into directory structure

[shadinua]

• added script to generating keys and placing them into appropriate directory structure
• added gen_keys target in Makefile to run generate-keys.sh script with default arguments

[vixentael]

Thank you, I think that this script is very useful for users.

However, I have doubts about gen_keys name. The Acra component name is acra-keymaker. Not sure if gen_keys is a best name, but I don't have any other suggestions really :/

By the way, can you please rename SERVICE_NAME from acra-genkeys into acra-keymaker?
https://github.com/cossacklabs/acra/blob/master/cmd/acra-keymaker/acra-keymaker.go#L29

I understand that it's outside of scope of this PR, I think we just forgot to fix the service name. But I strongly believe it will be better to add it to this PR 🙃

[shadinua]

Thank you for reply!

• I've renamed Makefile's target to keys, so the command will sound like make keys.
• I've fixed SERVICE_NAME.