Add Gustafson-Kessel clustering algorithm

[tomas-remis]

PR description

Implemented Gustafson-Kessel clustering algorithm.

Before

After

• Added Gustafson-Kessel in genfis.jl
• Added Gustafson-Kessel unit test in test_genfis.jl
• Added LinearAlgebra and Statistics packages as project dependencies

Related issues

Checklist

• [x] Added Gusstafson-Kessel base algorithm
• [x] Added tests
• [x] Added docstring
• [ ] Refactored/optimized code
• [ ] Unified Gustafson-Kessel and fuzzy c-means under AbstractFuzzyClustering

Other