BUG: malformed includes raises NoMethodError

从 JSONAPI::RequestParser#parse_include_directives 开始，跟踪 0.9 和 0.10 代码路径中调用 CSV.parse_line 的位置。复现来自 include[]=memberships 的数组输入，然后验证格式错误的输入不再引发未处理的 NoMethodError，而是作为 JSONAPI::Exceptions 错误返回。

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Description

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Bug reports:

The CSV gem raises a NoMethodError when passed an array

e.g. CSV.parse_line(["memberships"]) raises

private method `gets' called for ["memberships"]:Array

And JR in 0.9.x and 0.10.x in a few places uses CSV.parse_line but only rescues CSV::MalformedCSVError

making a request like v1/users/:id?include[]=memberships with call e.g. JSONAPI::RequestParser#parse_include_directives with ["memberships"] and raise an unhandled error.

My proposal is 1) encapsulate wherever CSV.parse_line is called and 2) ensure any errors are handled and raises as JSONAPI::Exceptions

I could possibly make PRs to 0.9 and 0.10

(We're still on 0.9 due to bugs changes in handling of polymorphic types and plain old resources, but I'd like to help however I can)