Remove rst2pdf because of build failures.

docs/Makefile

@@ -46,7 +46,6 @@ help:
 	@echo "  pseudoxml  to make pseudoxml-XML files for display purposes"
 	@echo "  linkcheck  to check all external links for integrity"
 	@echo "  doctest    to run all doctests embedded in the documentation (if enabled)"
-	@echo "  usermanual to make a PDF manual"
 	@echo "  coverage   to run coverage check of the documentation (if enabled)"
 	@echo "  serve      to serve the local html build on port 5000 for viewing"
 
@@ -178,11 +177,6 @@ doctest:
 	@echo "Testing of doctests in the sources finished, look at the " \
 	      "results in $(BUILDDIR)/doctest/output.txt."
 
-usermanual:
-	@echo "Running files through rst2pdf..."
-	$(SPHINXBUILD) -b pdf -D exclude_patterns="['_build', 'paradrop/paradrop.rst']" $(ALLSPHINXOPTS) $(BUILDDIR)/usermanual
-	@echo "Build finished; the PDF files are in $(BUILDDIR)/usermanual."
-
 coverage:
 	$(SPHINXBUILD) -b coverage $(ALLSPHINXOPTS) $(BUILDDIR)/coverage
 	@echo "Testing of coverage in the sources finished, look at the " \

docs/conf.py

@@ -46,7 +46,6 @@
 # extensions coming with Sphinx (named 'sphinx.ext.*') or your custom
 # ones.
 extensions = [
-    'rst2pdf.pdfbuilder',
     'sphinx.ext.autodoc',
     'sphinx.ext.intersphinx',
     'sphinx.ext.viewcode',
@@ -310,12 +309,6 @@
 # Example configuration for intersphinx: refer to the Python standard library.
 intersphinx_mapping = {'https://docs.python.org/': None}
 
-# -- rst2pdf output ------------------------------------------------------
-
-pdf_documents = [
-    ('index', u'rst2pdf', u'ParaDrop Manual', u'Paradrop Labs')
-]
-
 # -- Mock out modules -------------------------------------------
 
 # These modules use C extensions which cause trouble when building on

docs/requirements.txt

@@ -43,7 +43,6 @@ pytz==2017.3
 PyYAML==3.11
 reportlab==3.4.0
 requests==2.15.1
-rst2pdf==0.93.dev0
 service-identity==16.0.0
 six==1.10.0
 smokesignal==0.7.0