Test DevelopmentServerPane component

[AWolf81]

Related Issue:
#309

Summary:

• Test rendering (snapshot & no task rendered text)
• Test start / stop of devServer

[codecov]

Codecov Report

Merging #359 into master will increase coverage by 2.14%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #359      +/-   ##
==========================================
+ Coverage   29.32%   31.46%   +2.14%     
==========================================
  Files         160      159       -1     
  Lines        3823     3747      -76     
  Branches      420      424       +4     
==========================================
+ Hits         1121     1179      +58     
+ Misses       2435     2301     -134     
  Partials      267      267

Impacted Files	Coverage Δ
...nts/DevelopmentServerPane/DevelopmentServerPane.js	80.76% <ø> (+80.76%)	⬆️
src/components/Sidebar/Sidebar.js	100% <ø> (ø)	⬆️
src/components/Card/Card.js
src/components/LargeLED/LargeLED.helpers.js	20% <0%> (+20%)	⬆️
src/components/Toggle/Toggle.js	22.72% <0%> (+22.72%)	⬆️
src/components/OnlyOn/OnlyOn.js	23.52% <0%> (+23.52%)	⬆️
src/components/LargeLED/LargeLED.js	25% <0%> (+25%)	⬆️
src/components/TerminalOutput/TerminalOutput.js	28% <0%> (+28%)	⬆️
src/components/HelpButton/HelpButton.js	33.33% <0%> (+33.33%)	⬆️
src/components/Heading/Heading.js	41.66% <0%> (+41.66%)	⬆️
... and 4 more

[melanieseltzer]

LGTM!