More test and dead code removal

[tzaeschke]

No description provided.

[codecov]

Codecov Report

Merging #23 (5d3ffd2) into master (0b09a80) will increase coverage by 1.07%.
The diff coverage is 85.13%.

@@             Coverage Diff              @@
##             master      #23      +/-   ##
============================================
+ Coverage     72.72%   73.79%   +1.07%     
- Complexity     2035     2044       +9     
============================================
  Files            77       76       -1     
  Lines          8085     8007      -78     
  Branches       1588     1575      -13     
============================================
+ Hits           5880     5909      +29     
+ Misses         1819     1710     -109     
- Partials        386      388       +2     

Files Changed	Coverage Δ
...in/java/org/tinspin/index/covertree/CoverTree.java	75.84% <ø> (+3.65%)	⬆️
.../java/org/tinspin/index/rtree/RTreeMixedQuery.java	60.83% <0.00%> (ø)
...in/java/org/tinspin/index/rtree/RTreeQueryKnn.java	87.32% <87.32%> (+87.32%)	⬆️
src/main/java/org/tinspin/index/rtree/RTree.java	80.53% <100.00%> (+2.65%)	⬆️

... and 7 files with indirect coverage changes