Change IMU pose

[eborghi10]

Description

Following this design document, the idea of this PR is to adjust the pose of the IMU, based on the real robot data.

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

# See the pose of the robot in RViz (using Gazebo)
GUI=false RVIZ=true roslaunch ca_gazebo create_empty_world.launch

Test Configuration:

• Real robot
• Gazebo simulation
• Other (please specify)

Checklist:

• My code follows the style guidelines of this project (Travis CI is passing)
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes