Refactor spec helper not to duplicate configuration logic

Signed-off-by: Damien Le Berrigaud <damien@itsdamo.com>
Refactored TaskClient to be instantiated
RIntroduce dependency management to avoid usage of singletons and class methods

Signed-off-by: Damien Le Berrigaud <damien@itsdamo.com>
Merge pull request #77 from geapi/refactor_configuration

Configuration refactoring