Smac

* ADD 204: SMAC now always saves runhistory files as `runhistory.json`.
* MAINT 205: the SMAC repository now uses codecov.io instead of coveralls.io.
* ADD 83: support of ACLIB 2.0 parameter configuration space file.
* FIX 206: instances are now explicitly cast to `str`. In case no instance is
given, a single `None` is used, which is not cast to `str`.
* ADD 200: new convenience function to retrieve an `X`, `y` representation
of the data to feed it to a new fANOVA implementation.
* MAINT 198: improved pSMAC interface.
* FIX 201: improved handling of boolean arguments to SMAC.
* FIX 194: fixes adaptive capping with re-occurring configurations.
* ADD 190: new argument `intensification_percentage`.
* ADD 187: better dependency injection into main SMAC class to avoid
ill-configured SMAC objects.
* ADD 161: log scenario object as a file.
* ADD 186: show the difference between old and new incumbent in case of an
incumbent change.
* MAINT 159: consistent naming of loggers.
* ADD 128: new helper method to get the target algorithm evaluator.
* FIX 165: default value for par = 1.
* MAINT 153: entries in the trajectory logger are now named tuples.
* FIX 155: better handling of SMAC shutdown and crashes if the first
configuration crashes.

* Major speed improvements when sampling new configurations:
* Improved conditional hyperparameter imputation (PR 176).
* Faster generation of the one exchange neighborhood (PR 174).
* FIX 171 potential bug with pSMAC.
* FIX 175 backwards compability for reading runhistory files.

* CI only check code quality for python3.
* Perform local search on configurations from previous runs as proposed in the
original paper from 2011 instead of random configurations as implemented
before.
* CI run travis-ci unit tests with python3.6.
* FIX 167, remove an endless loop which occured when using pSMAC.

* MAINT refactor Intensifcation and adding unit tests.
* CHANGE StatusType to Enum.
* RM parameter importance package.
* FIX ROAR facade bug for cli.
* ADD easy access of runhistory within Python.
* FIX imputation of censored data.
* FIX conversion of runhistory to EPM training data (in particular running
time data).
* FIX initial run only added once in runhistory.
* MV version number to a separate file.
* MAINT more efficient computations in run_history (assumes average as
aggregation function across instances).

* FIX 124: SMAC could crash if the number of instances was less than seven.
* FIX 126: Memory limit was not correctly passed to the target algorithm
evaluator.
* Local search is now started from the configurations with highest EI, drawn by
random sampling.
* Reduce the number of trees to 10 to allow faster predictions (as in SMAC2).
* Do an adaptive number of stochastic local search iterations instead of a fixd
number (a5914a1d97eed2267ae82f22bd53246c92fe1e2c).
* FIX a bug which didn't make SMAC run at least two configurations per call to
intensify.
* ADD more efficient data structure to update the cost of a configuration.
* FIX do only count a challenger as a run if it actually was run
(and not only considered)(a993c29abdec98c114fc7d456ded1425a6902ce3).

* CI: travis-ci continuous integration on OSX.
* ADD: initial design for mulitple configurations, initial design for a
random configuration.
* MAINT: use sklearn PCA if more than 7 instance features are available (as
in SMAC 1 and 2).
* MAINT: use same minimum step size for the stochastic local search as in
SMAC2.
* MAINT: use same number of imputation iterations as in SMAC2.
* FIX 98: automatically seed the configuration space object based on the SMAC
seed.