Refractiveindex

[Diff since v0.4.0](https://github.com/stillyslalom/RefractiveIndex.jl/compare/v0.4.0...v0.4.1)

[Diff since v0.3.1](https://github.com/stillyslalom/RefractiveIndex.jl/compare/v0.3.1...v0.4.0)


**Merged pull requests:**
- Migrate from SnoopPrecompile to PrecompileTools (17) (timholy)

[Diff since v0.3.0](https://github.com/stillyslalom/RefractiveIndex.jl/compare/v0.3.0...v0.3.1)


**Closed issues:**
- Handle database entries with multiple dispersion data (14)

[Diff since v0.2.1](https://github.com/stillyslalom/RefractiveIndex.jl/compare/v0.2.1...v0.3.0)

[Diff since v0.2.0](https://github.com/stillyslalom/RefractiveIndex.jl/compare/v0.2.0...v0.2.1)

[Diff since v0.1.3](https://github.com/stillyslalom/RefractiveIndex.jl/compare/v0.1.3...v0.2.0)


**Closed issues:**
- Can't load refractive material with k values (12)

**Merged pull requests:**
- Update database (13) (mtenders)