Update gw likelilhood/prior tests

See merge request Monash/tupak!157

Merge branch '166-implement-caching-in-waveformgenerator-__parameters_from_source_model' into 'master'

Resolve "Implement caching in WaveformGenerator.__parameters_from_source_model"

Closes #166

See merge request Monash/tupak!153

Merge remote-tracking branch 'origin/master' into 166-implement-caching-in-waveformgenerator-__parameters_from_source_model

Simplifies some of the analytic 1D likelihoods

See merge request Monash/tupak!152

Add PyMC3 sampler

See merge request Monash/tupak!139

Replaced Analytical1DLikelihood._infer_parameters_from_function with utils function that is also used in the waveform generator

Merge branch '157-simplify-likelihoods' into 166-implement-caching-in-waveformgenerator-__parameters_from_source_model

Moved `infer_parameters_from_function` function here because it is used both in `waveform_generator` and `likelihood`

Refactored some old tests to make them separate and test one feature at a time