Fixed

.travis.yml

@@ -1,6 +1,5 @@
 language: python
 python:
-    - "3.5"
     - "3.7"
 install:
     - pip install .

setup.cfg

@@ -12,7 +12,6 @@ classifiers =
   Development Status :: 5 - Production/Stable
   Intended Audience :: Science/Research
   Programming Language :: Python :: 3
-  Programming Language :: Python :: 3.5
   Programming Language :: Python :: 3.7
   Topic :: Scientific/Engineering :: Bio-Informatics
   License :: OSI Approved :: GNU General Public License v3 (GPLv3)
@@ -22,7 +21,7 @@ long_description_content_type = text/markdown
 license_file = LICENSE
 
 [options]
-python_requires = >= 3.5
+python_requires = >= 3.7
 setup_requires =
   setuptools >= 38.6
   pip >= 10