Major updates for the integration into the IceSim framework

Bug Fixes

• modifications to embed into icesim (485ce0d5)
• errors and warnings in Integral (814d3e0f)
• photo unittest (bbdc8304)
• stochastic loss for ionization (1cf2a0a6)
• dont provide assignment op for sector def (ef1b754b)
• unset type in Converter (19668f61)
• correct conversion from PROPOSAL to icesim (0f1d06c5)
• add continuous loss output in pybindings (05af779b)
• uninitialized bug in FindLimit of Interpolant (3fe74069)
• check write permission on given paths (04dabc4b)
• print correct path in warning (aeb87cdb)
• icesim build (cb5d6592)

Features

• add medium pybind properties (e4c4bf4c)
• medium pybind gets a default argument (ba251c9e)
• I3: Finalize propagation with stoch Eloss (166f6f19)
• add distance to the propagator service (30519481)
• add 2 methods in MuonPropagator (4d1719f7)
• config file option "path_to_tables" (2c0ab383)

Core

• include googletest to the project (5ecbcda0)

Tests

• Fix propagation test (ed0f374f)
• add interpolation to photo script (61fbde5a)
• make scattering test more efficient (9eb25208)
• add all testfiles (14bf69e2)
• add test files for unit tests (81521992)
• add travis.yml to test the build process (52f36513)

Refactoring

• add equality operator for utility (ebac2fd7)

4.0.0

This release contains a full code restructuring.