mschauer/Bridge.jl: Release v0.6.0

This release contains a much improved implementation of guided proposals, which adopt a new interface. The corresponding improvements for partial guided bridges are postponed for the next release, so they still use the old interface.

• New scripts hypo.jl and elliptic.jl in the example directory to verify the correctness of the implementation.
• Fix: The llikelihood function is missing a factor -1/2 from the former likeliXcirc in SDE.jl, discovered by the method.
• Add a README.md file describing the examples
• Better test coverage