Importing pybgs crashes python runtime

**Describe the bug**

I have attempted to install `pybgs` both via `pip`:

```
pip install pybgs --force-reinstall --no-cache-dir
```

and from sources after cloning the repository via `setup.py`:

```
python setup.py build
python setup.py install
```

within a conda environment. In both cases I manage to install the library but when I attempt to import it the python runtime crashes:

```
$ python
Python 3.8.12 | packaged by conda-forge | (default, Oct 12 2021, 21:50:56)
[Clang 11.1.0 ] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import pybgs
Fatal Python error: _PyInterpreterState_Get(): no current thread state
Python runtime state: unknown

[1] 79583 abort python
```

**To Reproduce**

Install the library, either via pip or setup.py, and attempt to import it via `import pybgs`.

**Expected behavior**

The library is expected to import without crashing the python runtime.

### System information

**Desktop (please complete the following information):**
- **OS**: macOS 11.6
- **Python version**: 3.8.12
- **OpenCV version**: 3.4.7
- **conda version**: 4.10.3

**Additional context**

Building the library with CMake and running the example `run_video.sh` is successful. I have tried multiple different python versions, but the result is always the same.

**Installed packages**
```

# Name Version Build Channel
bzip2 1.0.8 h0d85af4_4 conda-forge
c-ares 1.17.2 h0d85af4_0 conda-forge
ca-certificates 2021.10.8 h033912b_0 conda-forge
cairo 1.16.0 he43a7df_1008 conda-forge
certifi 2021.10.8 py38h50d1736_0 conda-forge
cmake 3.19.6 h04fa861_0
cycler 0.10.0 py_2 conda-forge
expat 2.4.1 he49afe7_0 conda-forge
ffmpeg 4.1.3 h5c2b479_0 conda-forge
fontconfig 2.13.1 h10f422b_1005 conda-forge
freetype 2.10.4 h4cff582_1 conda-forge
gettext 0.19.8.1 hd1a6beb_1008 conda-forge
giflib 5.2.1 hbcb3906_2 conda-forge
gmp 6.2.1 h2e338ed_0 conda-forge
gnutls 3.6.13 h756fd2b_1 conda-forge
graphite2 1.3.13 h2e338ed_1001 conda-forge
harfbuzz 2.9.1 h159f659_1 conda-forge
hdf5 1.10.5 nompi_h500d6d3_1114 conda-forge
icu 68.1 h74dc148_0 conda-forge
imutils 0.5.4 py38h50d1736_0 conda-forge
jasper 1.900.1 h636a363_1006 conda-forge
jpeg 9d hbcb3906_0 conda-forge
kiwisolver 1.3.2 py38h12bbefe_0 conda-forge
krb5 1.19.2 h289aae4_2 conda-forge
lame 3.100 h35c211d_1001 conda-forge
lcms2 2.11 h11f7e16_1 conda-forge
libblas 3.9.0 12_osx64_openblas conda-forge
libcblas 3.9.0 12_osx64_openblas conda-forge
libcurl 7.79.1 h97da3c1_1 conda-forge
libcxx 12.0.1 habf9029_0 conda-forge
libedit 3.1.20191231 h0678c8f_2 conda-forge
libev 4.33 haf1e3a3_1 conda-forge
libffi 3.4.2 he49afe7_4 conda-forge
libgfortran 5.0.0 9_3_0_h6c81a4c_23 conda-forge
libgfortran5 9.3.0 h6c81a4c_23 conda-forge
libglib 2.70.0 hf1fb8c0_1 conda-forge
libiconv 1.16 haf1e3a3_0 conda-forge
liblapack 3.9.0 12_osx64_openblas conda-forge
liblapacke 3.9.0 12_osx64_openblas conda-forge
libnghttp2 1.43.0 hfd382f3_1 conda-forge
libopenblas 0.3.18 openmp_h3351f45_0 conda-forge
libopencv 3.4.7 py38_9 conda-forge
libpng 1.6.37 h7cec526_2 conda-forge
libssh2 1.10.0 hd3787cc_2 conda-forge
libtiff 4.1.0 ha78913b_3 conda-forge
libuv 1.42.0 h0d85af4_0 conda-forge
libwebp 1.0.2 hd3bf737_5 conda-forge
libxml2 2.9.12 h93ec3fd_0 conda-forge
libzlib 1.2.11 h9173be1_1013 conda-forge
llvm-openmp 12.0.1 hda6cdc1_1 conda-forge
lz4-c 1.9.3 he49afe7_1 conda-forge
matplotlib-base 3.4.3 py38hc7d2367_1 conda-forge
ncurses 6.2 h2e338ed_4 conda-forge
nettle 3.6 hedd7734_0 conda-forge
numpy 1.21.3 py38h49b9922_0 conda-forge
olefile 0.46 pyh9f0ad1d_1 conda-forge
opencv 3.4.7 py38_9 conda-forge
openh264 1.8.0 hd9629dc_1000 conda-forge
openssl 3.0.0 h0d85af4_1 conda-forge
pcre 8.45 he49afe7_0 conda-forge
pillow 8.1.0 py38hc1d52f7_1 conda-forge
pip 21.2.4 py38hecd8cb5_0
pixman 0.40.0 hbcb3906_0 conda-forge
py-opencv 3.4.7 py38h5ca1d4c_9 conda-forge
pybgs 3.0.0.post2 pypi_0 pypi
pyparsing 2.4.7 pyh9f0ad1d_0 conda-forge
python 3.8.12 h43ca1e7_2_cpython conda-forge
python-dateutil 2.8.2 pyhd8ed1ab_0 conda-forge
python_abi 3.8 2_cp38 conda-forge
readline 8.1 h05e3726_0 conda-forge
rhash 1.4.1 h35c211d_0 conda-forge
scipy 1.7.1 py38hd329d04_0 conda-forge
setuptools 58.2.0 py38h50d1736_0 conda-forge
six 1.16.0 pyh6c4a22f_0 conda-forge
sqlite 3.36.0 h23a322b_2 conda-forge
tk 8.6.11 h5dbffcc_1 conda-forge
tornado 6.1 py38h96a0964_1 conda-forge
wheel 0.37.0 pyhd8ed1ab_1 conda-forge
x264 1!152.20180806 h1de35cc_0 conda-forge
xz 5.2.5 haf1e3a3_1 conda-forge
zlib 1.2.11 h9173be1_1013 conda-forge
zstd 1.4.9 h582d3a0_0 conda-forge
```