Support Python 3.8 and use it for pre-commit and mypy

This is still a bit limited because a compatible
gevent version is not yet available for Python 3.8.

Author: Cito

.travis.yml

@@ -9,14 +9,16 @@ matrix:
        python: 3.6
     -  env: TOXENV=py37
        python: 3.7
+    -  env: TOXENV=py38
+       python: 3.8
     -  env: TOXENV=pypy
        python: pypy
     -  env: TOXENV=pypy3
        python: pypy3
     -  env: TOXENV=pre-commit
-       python: 3.7
+       python: 3.8
     -  env: TOXENV=mypy
-       python: 3.7
+       python: 3.8
 install: pip install coveralls tox
 script: tox
 after_success: coveralls
@@ -30,7 +32,7 @@ deploy:
   on:
     branch: master
     tags: true
-    python: 3.7
+    python: 3.8
   skip_existing: true
   user: syrusakbary
   password:

setup.py

@@ -70,6 +70,7 @@ def run_tests(self):
         "Programming Language :: Python :: 3.5",
         "Programming Language :: Python :: 3.6",
         "Programming Language :: Python :: 3.7",
+        "Programming Language :: Python :: 3.8",
         "Programming Language :: Python :: Implementation :: PyPy",
         "License :: OSI Approved :: MIT License",
         "Topic :: Database :: Front-Ends",

tox.ini

@@ -1,15 +1,15 @@
 [tox]
-envlist = py{27,35,36,37,py,py3},pre-commit,mypy,docs
+envlist = py{27,35,36,37,py38,py,py3},pre-commit,mypy,docs
 
 [testenv]
 deps =
     .[test]
 commands =
     py{27,py}: pytest graphql tests {posargs}
-    py{35,36,37,py3}: pytest graphql tests tests_py35 {posargs}
+    py{35,36,37,38,py3}: pytest graphql tests tests_py35 {posargs}
 
 [testenv:pre-commit]
-basepython=python3.7
+basepython=python3.8
 deps =
     pre-commit==1.21.0
 setenv =
@@ -18,7 +18,7 @@ commands =
     pre-commit {posargs:run --all-files}
 
 [testenv:mypy]
-basepython=python3.7
+basepython=python3.8
 deps =
     mypy==0.761
 commands =