Tell Travis to download Tesseract 4.00 from a PPA for testing

.travis/linux_before_install.sh

@@ -7,10 +7,6 @@ sudo add-apt-repository ppa:heyarje/libav-11 -y
 sudo apt-get update -qq
 sudo apt-get install -y \
 	ghostscript \
-	tesseract-ocr \
-	tesseract-ocr-deu \
-	tesseract-ocr-eng \
-	tesseract-ocr-fra \
 	qpdf \
 	poppler-utils \
 	libavformat56 \
@@ -18,6 +14,16 @@ sudo apt-get install -y \
 	libavutil54 \
 	libffi-dev
 
+sudo add-apt-repository ppa:alex-p/tesseract-ocr -y
+
+sudo apt-get update
+sudo apt-get autoremove -y
+sudo apt-get install -y --no-install-recommends \
+		tesseract-ocr \
+		tesseract-ocr-eng \
+		tesseract-ocr-fra \
+		tesseract-ocr-deu
+
 pip install --upgrade pip
 mkdir -p packages
 [ -f packages/unpaper_6.1-1.deb ] || wget -q https://dl.dropboxusercontent.com/u/28971240/unpaper_6.1-1.deb -O packages/unpaper_6.1-1.deb