drop py34

.travis.yml

@@ -6,7 +6,6 @@ cache:
   - "$HOME/.cache/pypoetry"
 python:
   - "2.7"
-  - "3.4"
   - "3.5"
   - "3.6"
   - "3.7"

pyproject.toml

@@ -42,7 +42,6 @@ classifiers = [
     "Programming Language :: Python :: 2",
     "Programming Language :: Python :: 2.7",
     "Programming Language :: Python :: 3",
-    "Programming Language :: Python :: 3.4",
     "Programming Language :: Python :: 3.5",
     "Programming Language :: Python :: 3.6",
     "Programming Language :: Python :: 3.7",
@@ -52,7 +51,7 @@ classifiers = [
 ]
 
 [tool.poetry.dependencies]
-python = "~2.7 || ^3.4"
+python = "~2.7 || ^3.5"
 
 [tool.poetry.dev-dependencies]
 sphinx = {version = "^2.1", python = "^3.7"}