Issue 695: Changing 'namespace_' variables to 'node_namespace' to make it more explicit

[bailaC]

Correcting the namespace to node_namespace. #695

[codecov]

Codecov Report

Attention: 2 lines in your changes are missing coverage. Please review.

Comparison is base (64c9e2a) 47.89% compared to head (6bb2353) 47.89%.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #1239   +/-   ##
=======================================
  Coverage   47.89%   47.89%           
=======================================
  Files          41       41           
  Lines        3451     3451           
  Branches     1876     1876           
=======================================
  Hits         1653     1653           
  Misses        444      444           
  Partials     1354     1354           

Flag	Coverage Δ
unittests	47.89% <33.33%> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

Files	Coverage Δ
...controller_interface/controller_interface_base.hpp	33.33% <ø> (ø)
.../include/controller_manager/controller_manager.hpp	18.18% <ø> (ø)
...roller_interface/src/controller_interface_base.cpp	48.14% <0.00%> (ø)
controller_manager/src/controller_manager.cpp	39.22% <50.00%> (ø)

[bmagyar]

Thank you!