fix(no_successive_maps): prevent failing on nested maps

[bormilan]

Description

I just added the option: traverse => all to the rule because when I investigated the problem with the provided example, I realized that the elvis_code:find does not go deep into this nested map, because the zippers can go deeper only if a node is a branch. A node is identified as a branch if it has something in its content field(if the traverse is set to content). So we need to change traverse to all so the elvis_code can use the node_attrs as the children of the node.

In this example, the rule fails because a map_field_assoc type node contains no content, preventing the function elvis_code:find from going deeper; it only returns that one map.

Closes #339.

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[paulo-ferraz-oliveira]

Looks Ok to me. Thanks.

[elbrujohalcon]

I don't understand how you made tests pass on OTP27, but the rest of the PR is cool.