Update .travis.yml

.travis.yml

@@ -2,6 +2,7 @@ language: python
 python:
   - "2.7"
 install:
+  - pip install --upgrade pip
   - pip install -r requirements.txt
   - pip install lxml --upgrade
   - pip install http://xmlsoft.org/sources/python/libxml2-python-2.6.21.tar.gz
@@ -11,11 +12,7 @@ script:
   coverage run --source=pytrustnfe setup.py nosetests
 before_install:
   - sudo apt-get update -qq
-  - sudo apt-get install -qq python-pip
-  - sudo apt-get install -qq libxml2-dev libxmlsec1-dev libxslt-dev 
-  - sudo apt-get install -qq python-dev python-lxml python-libxml2
-  - sudo apt-get install -qq python-libxslt1 libxml2
-  - sudo apt-get install -qq build-essential
+  - sudo apt-get install -qq libxml2-dev libxmlsec1-dev libxslt-dev
 after_success:
   coveralls