Merge branch 'bugfix/fix_importerror_spectral' into 'master'

Moved import of 'spectral' package to function level.

See merge request !12
5 jobs for v0.14.20 in 15 minutes (queued for 7 minutes and 33 seconds)
latest
Name Stage Failure
failed
deploy_anaconda Deploy Conda
ImportError: libpoppler.so.76: cannot open shared object file: No such file or directory
Tests failed for py_tools_ds-0.14.20-py35_1.tar.bz2 - moving package to /root/miniconda3/conda-bld/broken
WARNING:conda_build.build:Tests failed for py_tools_ds-0.14.20-py35_1.tar.bz2 - moving package to /root/miniconda3/conda-bld/broken
WARNING conda_build.build:tests_failed(2230): Tests failed for py_tools_ds-0.14.20-py35_1.tar.bz2 - moving package to /root/miniconda3/conda-bld/broken
export PREFIX=/root/miniconda3/conda-bld/py_tools_ds_1564142312243/_test_env_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_placehold_
export SRC_DIR=/root/miniconda3/conda-bld/py_tools_ds_1564142312243/test_tmp
import: 'py_tools_ds'
TESTS FAILED: py_tools_ds-0.14.20-py35_1.tar.bz2
ERROR: Job failed: exit code 1