mention pdf in introduction; use non-deb version for headless wkhtmltopdf

Author: nuest

.travis.yml

@@ -7,8 +7,10 @@ install:
  - "pip install mkdocs-cinder"
  - "pip install markdown-include"
  - "sudo apt-get install xfonts-base xfonts-75dpi"
- - "wget https://bitbucket.org/wkhtmltopdf/wkhtmltopdf/downloads/wkhtmltox-0.13.0-alpha-7b36694_linux-trusty-amd64.deb"
- - "sudo dpkg -i wkhtml*.deb"
+ - "wget https://github.com/wkhtmltopdf/wkhtmltopdf/releases/download/0.12.4/wkhtmltox-0.12.4_linux-generic-amd64.tar.xz"
+ - "tar -xvf wkhtmltox-0.12.4_linux-generic-amd64.tar.xz"
+ - "sudo mv wkhtmltox/bin/wkhtmltopdf /usr/bin/wkhtmltopdf"
+ - "wkhtmltopdf --version"
 after_success:
  - if [[ $TRAVIS_BRANCH == 'master' && $TRAVIS_PULL_REQUEST == 'false' ]]; then ./.deploy.sh ; fi
 env:

docs/01_introduction-and-goals.md

@@ -9,13 +9,17 @@ At its core is the concept of the **Executable Research Compendium** (ERC, see [
 The creation and inspection of ERCs are supported by a **reproducibility service**, which is defined by a [web **API** specification](http://o2r.info/o2r-web-api/) and demonstrated in a [**reference implementation**](https://github.com/o2r-project/reference-implementation).
 Both are published under open licenses, as is this document.
 
+A PDF version of this document is available for download at [http://o2r.info/architecture/o2r-architecture.pdf](http://o2r.info/architecture/o2r-architecture.pdf).
+The normative specification is given by the [Markdown](https://en.wikipedia.org/wiki/Markdown) in the [project repository](https://github.com/o2r-project/architecture/).
+
 ### 1.2 Quality Goals
 
 Transparency
 : The system must be transparent to allow scrutiny required by a rigorous scientific process.
+All components must be Free and Open Source Software ([FOSS](https://en.wikipedia.org/wiki/Free_and_open-source_software)).
 
 Separation of concern
-: The system must integrate with existing services and focus on the core functionality.
+: The system must integrate with existing services and focus on the core functionality: creating interactive reproducible runtime environments for scientific workflows.
 It must not replicate existing functionality such as storage or persistent identification.
 
 Flexibility & modularity