Refactored request module

Now caches all different types of requests
Fixed broken test by using tmp directory
Merge pull request #104 from jbeast/extra_caching

Refactored request module
Pico analysis working but not quite finished
Refactored pico analysis a little
Fixed stupid critic comment again
Small fixes
Pico analysis now fetches the files it needs

Uses FTP download
Refactored PDF generation a little
Pico analysis results mods

Now round results to 2 decimal places. Added a timestamp.
Fixed merge conflict
Plugged PDF creation into pico analysis

Made analysis_file a required attribute for file attachment
Moved some tests

Out of pdf_generator-worksheet and in to pdf_generator because
they are common
Merge pull request #106 from jbeast/pico_analysis

Pico analysis
Prep for release 0.33
Added to MANIFEST
Merge pull request #107 from wtsi-clarity/devel

Release 0.33