Upgraded library to work with specs-v1

[roll]

• fixes Sync with specs-v1 #32
• fixes Ensure there is no path traversing vulnerabilities #50
• fixes Issue with co2-pmm datapackage with raiseInvalid is false #53
• fixes Make constructor sync and Class.load async #24
• fixes Implement DataPackage.{get/remove}Resource #31
• fixes Datapackage class should be DataPackage #63
• fixes Consider using options argument instead of individual parameters #55

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@amercader
please take a look

Because of brithis holidays I've decided to put all changes into one PR to not be blocked. So there are many changes. I suppose the easiest way to review will be going commit by commit. Describing main steps:

• added specs-v1 jsonschemas using starndard to the stack way with up-to-date tests - 93dfd6f
• merged node/browser tests into one codebase because it was splited into two mostly identical copies making changing the actual codebase really difficult - 3696312
• introduced Profile class based on Python API - e5162ba
• updated Resource class based on Python implementation - b7d68a2
• update DataPackage class based on Python implementation - aa4b3a9

I would say the codebase state before this PR was more like a prototype so I've just ported many things from Python codebase. It was easier than twaeking existent ones. Especially it's related to tests - we had a really small amount of them. So now it's covered much better and also it uses many Python test cases so we aim here cross-language consistency in behaviour.

During this work I've tweaked API based on previosly raised issues and improved readme - https://github.com/frictionlessdata/datapackage-js/tree/specs-v1#datapackage-js (could be a good review start).

That the last PR for core libs to specs-v1 update.

[amercader]

All looks good @roll 👍

[roll]

@amercader
Thanks!