blender bulldozer 19

add empty -> plain axis, select camera then select axis, ctrl + p set parent

animation select frame 1, i -> rotation to insert frame, select frame 250

select axis r + z + 360 to rotate 360 degree, i -> rotation to insert frame

edit preference -> animation -> select linear as default interpolation

reference:

rotate camera

https://youtu.be/tj74-T2kqGU