Install python modules needed events and littlefs tests

Signed-off-by: Devaraj Ranganna <[email protected]>

Author: urutva

.travis.yml

@@ -196,6 +196,17 @@ matrix:
     - &extended-vm
       name: "events"
       env: NAME=events EVENTS=events
+      language: python
+      python: 3.7
+      install:
+        # Install gcc
+        - source_pkg gcc
+        - arm-none-eabi-gcc --version
+        # Install python modules
+        - python -m pip install --upgrade pip==18.1
+        - python -m pip install --upgrade setuptools==40.4.3
+        - pip install -r requirements.txt
+        - pip list --verbose
       script:
         # Check that example compiles
         - sed -n '/``` cpp/,/```/{/```$/Q;/```/d;p;}' ${EVENTS}/README.md > main.cpp