Try travis-trusty

This removes some backports for packages that Ubuntu trusty offers but
for which Ubuntu precise needed help.

.travis.yml

@@ -1,3 +1,5 @@
+sudo: required
+dist: trusty
 language: python
 
 cache: pip
@@ -10,15 +12,13 @@ cache:
 
 python:
     - 3.4
+    - 3.5
 
 before_cache:
     - rm -f $HOME/.cache/pip/log/debug.log
 
 before_install:
     # Ubuntu packages
-    - sudo add-apt-repository ppa:evl.ms/precise -y  # for Ghostscript 9.15
-    - sudo add-apt-repository ppa:lyrasis/precise-backports -y  # for Tesseract 3.03
-    - sudo add-apt-repository ppa:b-eltzner/qpdfview-exp -y  # for QPDF 5
     - sudo add-apt-repository ppa:itachi-san/ffmpeg -y  # for libav 11.2 (for unpaper)
     - sudo apt-get update -qq  # must go after all add-apt-repo
     - sudo apt-get install -y ghostscript tesseract-ocr tesseract-ocr-deu tesseract-ocr-eng tesseract-ocr-fra qpdf poppler-utils libavformat56 libavcodec56 libavutil54 libffi-dev