overriding simulator outputs with auto-batched inputs

[Kucharssim]

fixes #312

Example

def context():
    n = np.random.randint(10,100)
    return dict(n=n)

def prior(): 
    mu = np.random.normal(0,1)
    return dict(mu=mu)

def likelihood(mu, n):
    y = np.random.normal(mu,1,n)
    return dict(y=y)

simulator = bf.make_simulator([prior, likelihood], meta_fn=context)

simulator.sample(5, n=10, mu=100)

yields

{'n': 10,
 'mu': array([[100],
        [100],
        [100],
        [100],
        [100]]),
 'y': array([[ 98.90671933, 100.61462062, 100.42855418, 101.29272571,
          99.72418927,  99.37682655, 100.56386549, 100.6960222 ,
          99.68990492,  99.78906661],
        [ 98.30115229,  99.57536366, 100.8883384 ,  99.30972481,
          99.15394186,  99.50626826,  99.84819924,  99.34255664,
          99.72014674, 100.91778608],
        [100.14703062,  97.29856387, 100.26204114, 100.13075532,
          98.46860163,  99.74049941,  99.30891457,  97.92621077,
         100.65618885, 100.32520231],
        [ 99.40222488,  98.65323336, 100.45569538,  99.78072558,
          99.99451661,  99.14487046, 100.01430986, 102.46395478,
         100.37424699, 101.17221606],
        [ 99.82039995,  99.88639318,  98.72186382, 100.3090266 ,
          98.47726752, 100.42259135, 100.5953545 ,  98.9832539 ,
          98.12420365, 102.1115805 ]])}

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Files with missing lines	Coverage Δ
bayesflow/simulators/sequential_simulator.py	100.00% <100.00%> (ø)

... and 3 files with indirect coverage changes

[paul-buerkner]

Looks good to me, thank you! Would you mind adding a small test for the new feature?

@LarsKue would you mind quickly reviewing this PR too?

[LarsKue]

Thank you for the PR!

[paul-buerkner]

Great! Merging now :-)