Use 1.14 release of verapdf (#25)

Image for ruby:2.6 update and include
java 11
And verapdf 1.12 cause error while working with this java
See:
veraPDF/veraPDF-apps#254

.travis.yml

@@ -11,7 +11,7 @@ before_install:
   - gem update --system
 install:
   - bundle install --without development
-  - wget http://software.verapdf.org/releases/1.12/verapdf-greenfield-1.12.1-installer.zip -O /tmp/verapdf-installer.zip
+  - wget http://software.verapdf.org/releases/1.14/verapdf-greenfield-1.14.2-installer.zip -O /tmp/verapdf-installer.zip
   - unzip /tmp/verapdf-installer.zip -d /tmp/verapdf-installer
   - java -jar /tmp/verapdf-installer/*/verapdf-izpack-installer-*.jar verapdf-auto-install.xml
 script:

Dockerfile

@@ -7,7 +7,7 @@ RUN apt-get -y update && \
 
 # Install verapdf
 ADD verapdf-auto-install.xml /tmp/verapdf-auto-install.xml
-RUN wget http://software.verapdf.org/releases/1.12/verapdf-greenfield-1.12.1-installer.zip -O /tmp/verapdf-installer.zip
+RUN wget http://software.verapdf.org/releases/1.14/verapdf-greenfield-1.14.2-installer.zip -O /tmp/verapdf-installer.zip
 RUN unzip /tmp/verapdf-installer.zip -d /tmp/verapdf-installer
 RUN java -jar /tmp/verapdf-installer/*/verapdf-izpack-installer-*.jar /tmp/verapdf-auto-install.xml
 RUN rm -rf /tmp/verapdf*