Add base class to run sonar sputnik

Load sonar configuration specified in sputnik configuration file, build
a valid sonar configuration and run sonar runner inside the same process
running sputnik.

This is not fully functional as we need to parse sonar issues in order
to report them to sputnik.

Change-Id: I6117d97541b65a8c575cd178c948632ed7fe76fc
Adds a class to parse Sonar results.

SonarResultParser parses json result and produces a ReviewResult.

Change-Id: I11e2fc20567570343b20648f8d7ae8bc04d5940b
Adds a SonarProcessor class.

Change-Id: I86633f86858efbe9aaea177d68492c1ff937273e
Test that sonar parser only reports new issues

Add test fixtures that test sonar will only report new issues

Change-Id: I47dd6d4c088620bd5120a07a155e75ba0687b808
Use file basename instead of fullname in sonar

Some sonar plugin do no include git path as the source file path (for
example, sonar-visual-studio plugin generates filenames that are
relative to the module csproj file).

Using the file basename and a recursive match allows Sonar to match
modified files with their indexed names in Sonar.

Although this can generate useless analysis (as some files that are not
included in a review may be analysed), this has a limited additional
cost considering that few files have the same basename inside a
repository.

Change-Id: Ib74289e201098d15c618791f47b2dd657c3a1744
Update README

Add sonar as a tool for sputnik in the readme title

Change-Id: I53df772174a7b0478a992dc8a45c1cf844c8958b
Rename sonar configuration file key

As this configuration directive holds multiple configuration file paths
it has been renamed configurationFiles.

Change-Id: I33c4e37a8ac25a81868086a9bdd7d2c62685d517
Use TestEnvironment class and fix naming

Rename test and use TestEnvironment class as a base class for test
in order to use helper methods.

Change-Id: I413e2b5d536201dc59059b1fdc0a0c2c1073cc67
Add the rule name to sonar sputnik comment

Add the rule name so the user can access the description of this
rule to fix the issue

Change-Id: Icff9bdde4e520f1b6e09925ea6e03d0cd6a718ef