Add quickselect algorithm. Quickselect is a selection algorithm to find the kth smallest element in an unordered list.

1. go to https://graphhopper.com/maps/
2. from/to text fields are empty, click one of the vehicle icons
3. right click the map -> 'Set as Start/Intermediate/End' entries are grayed out
4. (bonus) click vehicle icon again -> markers are created in Sibay, Russia, context menu entries become active again, but from/to fields still empty even though there are markers on the map

I ran into build problem with tests. We may be missing a dependency check for spatialite-tools on a fresh build, but don't explicitly check for its existence when building the test target. As a result, the test target fails downstream when a require data dependency is missing.

Here's the error I got:

$ mkdir build
$ cmake 

This algorithm is simple and it would be a nice addition to a collection algorithms your library provides

Documentation and sample Python code can be found here
https://www.geeksforgeeks.org/articulation-points-or-cut-vertices-in-a-graph/

Mac OSX
QGIS 3.4

I get this error when I try to close QGIS and when I tried to reinstall the plugin

Error while unloading plugin QNEAT3 

KeyError: 'QNEAT3' 
Traceback (most recent call last):
  File "/Applications/QGIS3.4.app/Contents/MacOS/../Resources/python/qgis/utils.py", line 393, in unloadPlugin
    _unloadPluginModules(packageName)
  File "/Applications/QGIS3.4.app/Conten

$ sbt runMain com.github.graphx.pregel.ssp.demo.ShortestPathProblemDemo
[info] Loading settings from plugins.sbt ...
[info] Loading project definition from /home/mahboob/Code/latest/spark/introduction-to-spark/spark-graphx/project
[info] Loading settings from build.sbt ...
[info] Set current project to spark-graphx (in build file:/home/mahboob/Code/latest/spark/introduction-to-spark/spark-grap