update to the last implementation
moved the no damage limit in the fragility function
Removed gmf_collection.complete_logic_tree_gmt and gmf_set.complete_logic_tree_ses
Removed complete_logic_tree_ses in the table ses and ses_collection
Merge pull request #1095 from gem/remove_complete_logic_tree_flags

Remove complete logic tree flags when redundant
Merge pull request #1090 from matley/fragility-sd-imt

Fragility model using structure dependent IMT
tests/db/models_test:

Cleaned up a test setUp to use engine2 instead of engine.
tests/job_test:

Deleted some obsolete tests.
tests/performance_monitor_test:

Use engine2 instead of engine.
tests/supervisor_test:

Use engine2 instead of engine.
tests/utils_*:

Use engine2 instead of engine.
tests/engine_test:

Removed tests for an obsolete module.
tests/utils/helpers:

Removed a dependancy on `engine` module, and remove an unused util function.
tests/utils/helpers:

Deleted another unused function, removing completely the dependancy on engine.
engine: Removed.
engine2 -> engine
s/engine2/engine/g

... to match the renamed module.
tools/performance/serialization_speedtests:

Removed.
tests/db/model_risk_exposure_test:

Use hazardlib.geo instead of shapes.
tests/shapes_test:

Removed the test module for `shapes`.