MAINT: fix a couple of typos.

Author: rgommers

.travis/run.sh

@@ -2,12 +2,12 @@
 set -e
 set -x
 
-# If we're running under Python 3.5, we can't use anything but --asert=plain
+# If we're running under Python 3.5, we can't use anything but --assert=plain
 if [[ $TOXENV = "py35" ]]; then
     export TOXARGS="--assert=plain"
 fi
 
-# If we're running under Python 3.6, we can't use anything but --asert=plain
+# If we're running under Python 3.6, we can't use anything but --assert=plain
 if [[ $TOXENV = "py36" ]]; then
     export TOXARGS="--assert=plain"
 fi