Set explicetly installing junit-xml

.travis.yml

@@ -12,7 +12,8 @@ env:
   - BOTO_CONFIG=/dev/null
 install:
   - pip install -U pip wheel setuptools
-  - "pip install -r testrequirements.txt"
+  - pip install junit-xml~=1.9
+  - "pip install --no-binary :all: -r testrequirements.txt"
   - pip install -r requirements.txt
   - pip install -e .
 cache: