Add planner_dart component for DART planners

[gilwoolee]

This PR creates planner_dart component and builds all DART planners as planner_dart component.

---

Before creating a pull request

• Document new methods and classes
• Format code with make format

Before merging a pull request

• Set version target by selecting a milestone on the right side
• Summarize this change in CHANGELOG.md
• Add unit test(s) for this change

[sniyaz]

Hey @brianhou, can you take another look? Reviving this now, I've made some fixes so Travis should be satisfied.

[aditya-vk]

Looks mostly good! However, what is our current policy on creating a new component? Is it mostly for better organization (in which case it does not have to be a component that can be compiled optionally) or is it based on the dependencies involved? Whichever it is, we should document this. Could you create an issue to discuss, track and add the decision to our code guidelines?

[aditya-vk]

We do not need to check boost version here since this subdirectory does not have ompl code.

[sniyaz]

This is related to the below comment as well: this PR is set up for #566. Sorry, I totally should have made that more clear: because the ultimate goal here is deprecating a lot of the old robot/util stuff, we need to move some of the planTo methods that use ompl into this new dart_planner module. That's what #566 starts to do, but we set up the ompl dependency here 😄

[aditya-vk]

do we need ompl here?

[sniyaz]

See previous comment! 😸

[sniyaz]

@aditya-vk You have a good question about when to split off a new component. I think the motivation here is a combination of:

1. The amount of code in this component has grown large enough that splitting it off makes sense.
2. The dependency here on OMPL means that none of our planners would build if OMPL was not installed correctly (assuming we were using a single component for all planners like we have now).

If these motivations sound good, I'm happy to create an issue to track this and update our AIKIDO guidelines.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 78.69%. Comparing base (8e2bcd9) to head (a3654af).
⚠️ Report is 22 commits behind head on master.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #567      +/-   ##
==========================================
+ Coverage   76.37%   78.69%   +2.31%     
==========================================
  Files         200      170      -30     
  Lines        7030     6406     -624     
==========================================
- Hits         5369     5041     -328     
+ Misses       1661     1365     -296     

see 32 files with indirect coverage changes

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.