Juno ISIS Driver (#290)

* Added initial juno driver

* Added test data for juno

* Added juno workspace notebook

* Updated starting ephemeris time based on isis implementation

* Added testing for juno and updated the sliced kernels

* Removed juno workspace notebook

* Reset kernel slicing notebook

* Reverted data_naif sun position

* Updated juno test with center ephem for sun

* Removed duplicate isis label

* Added doc strings to test