fixed geochoropleth chart issue

[luukgruijs]

Merge Checklist

:wrench: Issue(s) fixed:

• [ ] Author referenced issue(s) fixed by this PR:
• [ ] Fixes #0

:smoking: Smoke Test

• [ ] Works in chrome
• [ ] Works in firefox
• [ ] Works in safari
• [ ] Works in ie edge
• [ ] Works in ie 11

:ship: Merge

• [ ] author crafted PR's title into release-worthy commit message.

There is an issue when using the geoChoroplethChart. If you just supply a normal selector when initiating the chart, there is no parent.attributes.id.value. Apparently you only use this when doing stuff with maps, so i moved it into the conditional check.

[codecov-io]

Codecov Report

Merging #125 into master will decrease coverage by <.1%. The diff coverage is 0%.

@@           Coverage Diff            @@
##           master    #125     +/-   ##
========================================
- Coverage    32.4%   32.4%   -0.1%     
========================================
  Files          72      72             
  Lines        8203    8203             
========================================
- Hits         2659    2658      -1     
- Misses       5544    5545      +1

Impacted Files	Coverage Δ
src/charts/geo-choropleth-chart.js	18.1% <0%> (-0.7%)	:arrow_down:

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