Fix broken test due to fltpt precission FeaturesTests.FftAggregated

[marregui]

74/211 Test  #74: FeaturesTests.FftAggregated ......................................***Failed   11.05 sec
Running main() from C:\dev\vcpkg\buildtrees\gtest\src\ase-1.10.0-9cde347ce0.clean\googletest\src\gtest_main.cc
Note: Google Test filter = FeaturesTests.FftAggregated
[==========] Running 1 test from 1 test suite.
[----------] Global test environment set-up.
[----------] 1 test from FeaturesTests
[ RUN      ] FeaturesTests.FftAggregated
←[32m[----------]←[0m CPU backend, device: Intel CPU
[----------] CUDA backend, device: GeForce_RTX_2060
←[32m[----------]←[0m OPENCL backend, device: GeForce_RTX_2060
←[32m[----------]←[0m OPENCL backend, device: Intel(R)_UHD_Graphics
←[32m[----------]←[0m OPENCL backend, device: Intel(R)_Core(TM)_i7-10875H_CPU @ 2.30GHz
C:\Users\MiguelArregui\workspace\khiva\test\featuresTest.cpp(481): error: The difference between fft[3] and f4 is 1.1920928955078125e-06, which exceeds EPSILON, where
fft[3] evaluates to 3.642664909362793,
f4 evaluates to 3.6426661014556885, and
EPSILON evaluates to 9.9999999999999995e-07.
[  FAILED  ] FeaturesTests.FftAggregated (10790 ms)
[----------] 1 test from FeaturesTests (10790 ms total)

[----------] Global test environment tear-down
[==========] 1 test from 1 test suite ran. (10790 ms total)
[  PASSED  ] 0 tests.
[  FAILED  ] 1 test, listed below:
[  FAILED  ] FeaturesTests.FftAggregated

1 FAILED TEST