[MINOR] Fix python test typo?

I suspect haven't been using anaconda in tests in a while. I wonder if this change actually does anything but this line as it stands looks strictly less correct.

Author: Andrew Or <andrew@databricks.com>

Closes #5883 from andrewor14/fix-run-tests-typo and squashes the following commits:

a3ad720 [Andrew Or] Fix typo?

dev/run-tests

@@ -236,7 +236,7 @@ echo "========================================================================="
 CURRENT_BLOCK=$BLOCK_PYSPARK_UNIT_TESTS
 
 # add path for python 3 in jenkins
-export PATH="${PATH}:/home/anaonda/envs/py3k/bin"
+export PATH="${PATH}:/home/anaconda/envs/py3k/bin"
 ./python/run-tests
 
 echo ""