RSA keylength, keys directory permissions, remove pause module

[jeanmonet]

Referring to the following opened issues:

• opendkim-keygen: variable to allow 2048/4096 key instead of the default 1024 #9
• Error using 'pause' module in dns_records.yml task file #10
• Permissions/ownership on /etc/opendkim folder and key/ subfolder #11

Proposals:

• create variable dkim_rsa_keylen that allows to set a custom length for the generated RSA key
• use debug module instead of pause to print public key/DNS TXT record to screen
• ensure ownership by opendkim (or group set in dkim_group variable) of the ../keys/ directory, in order for opendkim to be able to read the private key file

[foxycode]

Sorry for late answer. Will merge after you update. Thanks.

[jeanmonet]

@foxycode Thanks for review. Before I update the PR, would you mind re-checking your suggestion on defaults/main.yml ? I think a default value for dkim_rsa_keylen would be needed to pass it to tasks/opendkim_keys.yml explicitly if it's not set by the user.

[foxycode]

Great, thanks :)