Try this

francozappa · francozappa · commit 97482892b4b7 · 2017-04-10T08:55:47.000+08:00
diff --git a/.travis.yml b/.travis.yml
@@ -23,7 +23,9 @@ python:
 
 # NOTE: Travis-ci automatically runs
 #
-# pip install -r requirements.txt
+install:
+  sudo pip install -r requirements.txt
+  pip install -r requirements.txt
 
 # TODO: Add mininet-based tests
 script: make tests-travis

Original file line number	Diff line number	Diff line change
`@@ -23,7 +23,9 @@ python:`
`23`	`23`
`24`	`24`	`# NOTE: Travis-ci automatically runs`
`25`	`25`	`#`
`26`		`-# pip install -r requirements.txt`
	`26`	`+install:`
	`27`	`+ sudo pip install -r requirements.txt`
	`28`	`+ pip install -r requirements.txt`
`27`	`29`
`28`	`30`	`# TODO: Add mininet-based tests`
`29`	`31`	`script: make tests-travis`