take into account the outdir document attribute if specified
Only use fixed image size when the backend is html5
Merge pull request #31 from neher/issue30

Take into account the outdir document attribute if specified
Add test case for outdir attribute
Ensure image target directory exists before attempting to write file
Detect HTML backends using regexp rather than exact 'html5' string comparison
Add spec for omitting width/height in docbook output
Merge pull request #1 from pepijnve/fixed_image_size

Fixed image size
Merge branch 'master' of https://github.com/asciidoctor/asciidoctor-diagram into fixed_image_size

Conflicts:
	spec/plantuml_spec.rb
Merge pull request #32 from neher/fixed_image_size

Only generate width and height attributes when the backend is an html one
Bump version number
Update changelog
Merge branch 'master' into asciidoctor-1.5

Conflicts:
	CHANGELOG.adoc
	lib/asciidoctor-diagram/version.rb