Remove python 3.4 tests

BioPython now requires 3.6. TRAL should still work on 3.4 using older
BioPython versions, but let's drop official support.

Author: sbliven

.travis.yml

@@ -1,6 +1,5 @@
 language: python
 python:
-  - "3.4"
   - "3.6"
 # command to install dependencies
 install:

setup.py

@@ -38,6 +38,8 @@ def read(*paths):
         "Intended Audience :: Developers",
         "Programming Language :: Python",
         "Programming Language :: Python :: 3",
+        "Programming Language :: Python :: 3.6",
+        "Programming Language :: Python :: 3.7",
         "Natural Language :: English",
         "Topic :: Software Development",
         "Topic :: Scientific/Engineering",