Fix/geotf

[rikba]

Problem: The conversion from SBP ECEF or WGS84 measurement to ENU with geotf was erroneous because of the projection type geotf uses (see ethz-asl/geodetic_utils#53).

In this PR we replace geotf by geographiclib which gives conversions between ECEF<->WGS84<->ENU.

We tested this PR with historic data in a unit test as well as on the hardware. Here we set up the base station approximately 250m away from the rover and set the base station antenna position to be the ENU origin. pos_enu published by our driver and baseline_ned published by Piksi should now coincide.

OLD master

/rover/piksi/position_receiver_0/ros/pos_enu
  east: 46.169826148400524
  north: -244.57162264061503
  up: -4.039364604279399

/rover/piksi/position_receiver_0/ros/baseline_ned
  east: 46.257
  north: -244.28
  up: -4.0440000000000005

Difference: 0.304 This is terrible!

New fix/geotf

/rover/piksi/position_receiver_0/ros/pos_enu
  east: 46.27259394353746
  north: -244.25576613787558
  up: -4.042596601441858

/rover/piksi/position_receiver_0/ros/baseline_ned
  east: 46.273
  north: -244.256
  up: -4.043

Difference: 0.0006 This is excellent! It is within the mm resolution of baseline_ned.

This PR closes #227

[rikba]

This also reduces catkin dependencies.