generate delaunay tr: more triangles than real

[demanasta]

Describe the bug
delaunauy def generate fake triangles or unnecessary triangles if stations are very close together. -> wrong results

• check the shape of the triangles? angles?

To Reproduce

1. ./bin/StrainTensor.py -i ../test_data/data/ntua_repro17.vel --region=18/30/32/44 --method veis
2. ./plot/gmtstrainplot.sh -jpg -str strain_info.dat -psta -l -o output_str -deltr -strsc 0.00011

Desktop (please complete the following information):

• OS: [Ubuntu 18.04]
• Python: [2.7/3.6]
• GMT: [5.2.1]
• StrainTool: [v1.0]

Additional context
Add any other context about the problem here.