Bearer only client

[lodrantl]

Resolves #26.

[Trojan295]

@lodrantl, could you rebase the PR from the current master? There was a problem with CI, which is fixed now.

[coveralls]

Pull Request Test Coverage Report for Build 63

• 14 of 14 (100.0%) changed or added relevant lines in 1 file are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage increased (+0.5%) to 55.318%

---

Files with Coverage Reduction	New Missed Lines	%
./test/unit/mockable_case.lua	1	97.83%
<!--	Total:	1		-->

Totals
Change from base Build 60:	0.5%
Covered Lines:	1061
Relevant Lines:	1918

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💛 - Coveralls

[lodrantl]

Finnally took the time to rebase and add the tests. Also deployed it to staging env and we'll see how it goes.

[tsyrjanen]

Looks good. @phirvone could you also look at this.