Improve unit test coverage in core

Convolution

• ConstantConvolver
• AnnularConvolver
• RadialConvolver
• EnhancedAnnularConvolver
• CentralDifference
• PrewittConvolver
• RobertsConvolver
• SobelConvolver
• Sobel5Convolver

Data

• DataSet
• SingleFrame

Detector

• DetectorEvent
• Detector (base class)

Experiment

• DataHandler
• Experiment
• InstrumentStateHandler
• MaskImporter
• MaskExporter
• MtzImporter
• MtzExporter
• PeakHandler
• ShapeHandler
• UnitCellHandler
• ExperimentYAML

Gonio

• Axis
• Gonio

Instrument

• Diffractometer
• InstrumentStateSet
• MatrixOperations
• Monochromator
• Sample
• Source

Integration

• PixelSumIntegrator
• GaussianIntegrator
• IIntegrator
• ISigmaIntegrator
• Profile1DIntegrator
• Profile3DIntegrator
• ShapeIntegrator

Loader

• HDF5DataReader
• NexusDataReader
• PlainTextReader
• TiffDataReader
• RawDataReader

Peak

• IntegrationRegion
• Intensity
• PeakCoordinateSystem
• PeakData
• RegionData

Raw

• MetaData
• HDF5TableIO

Shape

• KeyPointCollection
• PeakCollection
• Profile1D
• Profile3D

Statistics

• CC
• MergedPeakCollection
• MergedPeak
• PeakExporter
• PeakMerger
• PeakStatistics
• ResolutionShell
• RFactor
• RotationSlice