Merge pull request #723 from awwright/update-xml2rfc

Update xml2rfc required version

Author: handrews

Diff for: .travis.yml

@@ -1,9 +1,8 @@
 language: python
 install:
-- pip install "xml2rfc<2.10"
+- pip install "xml2rfc~=2.20"
 before_script:
 - TAG=$(git tag -l --points-at HEAD)
 script:
-- xml2rfc jsonschema-core.xml --basename=jsonschema-core-$TAG --text --html
-- xml2rfc jsonschema-validation.xml --basename=jsonschema-validation-$TAG --text --html
-- xml2rfc jsonschema-hyperschema.xml --basename=jsonschema-hyperschema-$TAG --text --html
+- xml2rfc -V
+- make all