Add Python 3.8 to CI tests.

.gitignore

@@ -64,3 +64,9 @@ notebooks/unfinished
 gklearn/kernels/else/
 gklearn/kernels/unfinished/
 gklearn/kernels/.tags
+
+# pyenv
+.python-version
+
+# docker travis debug.
+ci.sh

.travis.yml

@@ -3,7 +3,7 @@ python:
 - '3.5'
 - '3.6'
 - '3.7'
-# - '3.8'
+- '3.8'
 before_install:
 - python --version
 - pip install -U pip
@@ -13,10 +13,7 @@ before_install:
 - pip install pytest-cov
 
 install:
-- if [ $TRAVIS_PYTHON_VERSION == 3.8 ]; 
-  then pip install -r gklearn/tests/requirements.txt;
-  else pip install -r requirements.txt;
-  fi
+- pip install -r requirements.txt
 - pip install wheel
 
 script: