Lofreq vcfplot - python version 3 support

[saradunaj]

Hi, Curious when or how to best modify your vcfplot script to work with python 3. I tried both the conda installation of lofreq and I tried directly running your repo's lofreq v2 script and I get the same error:

/lofreq/src/tools/scripts/lofreq2_vcfplot.py lofreq.vcf

Traceback (most recent call last):
File "/lofreq/src/tools/scripts/lofreq2_vcfplot.py", line 54, in
from lofreq_star.utils import complement, now
File "/lofreq/src/tools/lofreq_star/init.py", line 2, in
assert sys.version_info.major == 2 and sys.version_info.minor == 7, ("Need Python 2.7")
AssertionError: Need Python 2.7