v0.4.0

Chuffed v0.4.0

Merged pull requests:

• Add license headers (#4) (@odow)
• Add CI (#5) (@odow)
• Update to MOI v1 (#7) (@blegat)
• Update to ConstraintProgrammingExtensions v0.7 (#10) (@blegat)

Closed issues:

• Run the test suite on GitHub Actions (#1)
• Move code to CP.jl (#2)
• Create a README (#3)