CI: Test Python 3.8

Author: effigies

.travis.yml

@@ -7,9 +7,8 @@ python:
 - 3.5
 - 3.6
 - 3.7
+- 3.8
 
-# NOTE: Any changes to the matrix section should be duplicated below for
-#       Python 3.4
 env:
   global:
     - EXTRA_WHEELS="https://5cf40426d9f06eb7461d-6fe47d9331aba7cd62fc36c7196769e4.ssl.cf2.rackcdn.com"
@@ -28,7 +27,7 @@ env:
       CI_SKIP_TEST=1
     - INSTALL_DEB_DEPENDECIES=true
       NIPYPE_EXTRAS="doc,tests,nipy,profiler"
-      EXTRA_PIP_FLAGS="--pre $EXTRA_PIP_FLAGS --find-links $PRE_WHEELS"
+      EXTRA_PIP_FLAGS="--pre $EXTRA_PIP_FLAGS --find-links $PRE_WHEELS --upgrade"
       CI_SKIP_TEST=1
 
 matrix: