v0.4.0

CalibrationTests v0.4.0

Diff since v0.3.0

Merged pull requests:

• Update CI and add bors (#13) (@devmotion)
• Replace AppVeyor with Github Actions (#14) (@devmotion)
• Update HypothesisTests (#16) (@devmotion)
• Update README.md (#17) (@devmotion)
• Update bors.toml (#18) (@devmotion)
• Update CalibrationErrors (#19) (@devmotion)