Add testing for 3.7 and 3.8

.travis.yml

@@ -1,6 +1,8 @@
 # Config file for automatic testing at travis-ci.org
 # This file will be regenerated if you run travis_pypi_setup.py
 
+dist: xenial
+
 language: python
 
 matrix:
@@ -9,6 +11,10 @@ matrix:
       env: TOXENV=py27
     - python: "3.6"
       env: TOXENV=py36
+    - python: "3.7"
+      env: TOXENV=py37
+    - python: "3.8-dev"
+      env: TOXENV=py38
 
 install: pip install -U tox
 

README.md

@@ -1,6 +1,6 @@
 ![Cover Image](https://raw.githubusercontent.com/maebert/shellcraft/HEAD/docs/img/cover.png)
 
-ShellCraft is a game about mining, crafting, and puzzling, loosely based on Ted Chiang's short story *[Seventy-Two Letters](https://maebert.github.io/shellcraft/72letters)
+ShellCraft is a game about mining, crafting, and puzzling, loosely based on Ted Chiang's short story *[Seventy-Two Letters](https://maebert.github.io/shellcraft/72letters)*
 
 ```sh
 # Install ShellCraft

docs/installation.md

@@ -8,7 +8,7 @@ To install ShellCraft, run this command in your terminal:
 $ pip install shellcraft
 ```
 
-This is the preferred method to install ShellCraft, as it will always install the most recent stable release. This requires Python 2.7, or Python 3.3 or newer.
+This is the preferred method to install ShellCraft, as it will always install the most recent stable release. This requires Python 2.7, or Python 3.6 or newer.
 
 If you don't have [pip](pip) installed, this [Python installation guide](python-guide) can guide you through the process.