[Diff since v1.1.0](v1.1.0...v1.2.0)

- Fix QPO normalisation to make it consistent
    - Harmonise the normalisation of the power spectrum models for CARMA, Bending power-law, QPO such that the autocovariance and the power spectra are proper Fourier pairs

**Merged pull requests:**
- Fix normalisations and QPOs (#42) (@mlefkir)

Bump version from 1.0.0 to 1.1.0

Merge pull request #40 from mlefkir/QPOs2

Add QPOs and sine waves

update version and readme

version to 0.1.6

update compat

update version

Update README.md

Update Project.toml

update readme