Added more tests. 1. Added tests for frames which contain no data. Heliographic frames now function as defined in the previous commit when they have no data. 2. Added tests for repr() functionality of frame instances.
Added more tests.
1. Added tests for frames which contain no data. Heliographic frames now function as defined in the previous commit when they have no data.
2. Added tests for repr() functionality of frame instances.

dpshelio/sunpy,Alex-Ian-Hamilton/sunpy,Alex-Ian-Hamilton/sunpy,dpshelio/sunpy,dpshelio/sunpy,Alex-Ian-Hamilton/sunpy