add tests for loading user schema with abase

[SimonLab]

The goal of this PR is to initialise the plugin and to validate the options passed to the plugin: when a user register abase to their application:

server.register({register: abase, options: {user_schema_path: "./schema.json"}, (err) => {...})

the plugin check that:

• the options as the property user_schema_path defined
• The content of the schema is a json object
• Add default properties "email" and "password" if they are not yet defined and save the file

@jrans @eliascodes @nelsonic ready for review

next step #42

@jrans : This PR also does:

• properly sets up coverage generation.
• Adds travis badge

[nelsonic]

@SimonLab https://www.youtube.com/watch?v=XAIKGQacmU8

[jrans]

@SimonLab related Issues? none found in commits or PR desciption except for whats next.

[SimonLab]

@jrans #30 #13 and #43

[jrans]

@SimonLab When linter set up I think we'll have some problems, so should we do that before PR or fix stuff later?

[SimonLab]

@jrans goodparts has now all the rules defined so I'm going to try to use it on pre commit, so yes maybe we should hold on for now and I'm going to add a new commit

[codecov-io]

Current coverage is 100% (diff: 100%)

No coverage report found for master at 4f07f8b.

Powered by Codecov. Last update 4f07f8b...6d937a5

[jrans]

This PR also seems to resolve #47

@shouston3 left one more comment which is very simple

@nelsonic: @eliascodes and I happy now, do you want to make the final merge?

[nelsonic]

@SimonLab looks good. 👍 ❤️ ✅ :shipit:

Note: I had a quick chat with others regarding the fact that this PR including all the functionality in a single repo without splitting things out into independently tested plugins. This is fine for an MVP but we need to get to the point where we composing from smaller pieces. see: https://en.wikipedia.org/wiki/Unix_philosophy