Adds a line to print the result and indicate where results are saved

added the possibility to change the color scheme of corner plots with the 'lionize' keyword argument

Makes the decoding less aggressive. This was causing various things to
be coerced into a list when they where dictionaries etc.

- Renames run_sampler to run_external_sampler to differentiate it from
  the tupak run_sampler command
- Minor fixes elsewhere to code

- Renames the functin to show it is the `posterior` attribute which is
  generated

- Add the label to the saved prior
- Remove obsolete write function

Fixes one issue in #75

Fix one of the sub issues in #75. Namely plot_corner will now run for
data generated by python 2 when imported into python 3

- Fixes bug when setting truths
- Remove mu=None, sigma=None in hyper PE example

 Removes chainconsumer and following requirements. These where causing
the CI to be very slow. Instead, rather than plotting, just list a
warning.

- Adds a tests flag for which the sampler only runs 100 steps
- Set the samples as random samples to test plotting
- Fix problems in a few of the examples

- Adds a filename option for direct loading
- Raise an error if no information given

- If the sampler kwargs are the same
- If the search parameter keys are the same

MISSING: check the priors. This requires a more detailed look into how
to compare our prior distribtions.

This demotes CC from a requirement to something optional. If
`ChainConsumer` is called when it is not installed, a warning message is
raised.

- Add ability to pass in parameters as either keys or latex labels
- Update truth to not overwrite the given kwarg, but preserve "plot
  injections by default" behaviour.
- Add function to convert a set of parameter_keys into the latex labels
  used by CC

1) Remove the prior from the result object: we already save them as a
text file, so I don't think they need to be in the result. For now, I've
only commented them out with a message as there may be someone tempted
in the future to add it back in.

2) If the saving data does error, it now continues (without writing the
data) and prints a big error message.