Merge branch 'master' of https://github.com/tommyod/KDEpy into appveyor2

Merge branch 'master' of https://github.com/tommyod/KDEpy into appveyor

Appveyor (tommyod#68)

* Appveyor cert

* Removed export

* New attempt

* Cleaned appveyor

* version bump

Changed wheelhouse path (tommyod#67)

* Changed wheelhouse path

* Bumped version

Fixed bug in exponential kernel, added examples to docs (tommyod#66)

* added test for kernel functions to have unit standard deviation

* fixed bug related to variance of exponential kernel

* added new example to docs

* test should run now

* example evaluating on arbitrary grid

* cleaned up docs a bit

* appveyor echos

* cleaned up travis file

* bumped version

* appveyor echos

* appveyor echos

ran black v20 (tommyod#61)

Only build wheels on py36 through py38 (tommyod#43)

resolved merge. version 1.0.2

increased version to 1.0.1

Merge branch 'master' of https://github.com/tommyod/KDEpy