Use pipenv to lock dependencies

.travis.yml

@@ -1,11 +1,20 @@
 sudo: false
 
+language: python
+
+matrix:
+    include:
+        - python: 3.7
+          dist: xenial
+          sudo: true
+
 addons:
     apt_packages:
         - enchant
 
 install:
-    - pip install --user -r requirements.txt
+    - pip install pipenv
+    - pipenv install
 
 script:
     - make SPHINXOPTS='-nW' html

Makefile

@@ -2,15 +2,10 @@
 
 # You can set these variables from the command line.
 SPHINXOPTS    =
-SPHINXBUILD   = sphinx-build
+SPHINXBUILD   = pipenv run sphinx-build
 PAPER         =
 BUILDDIR      = _build
 
-# User-friendly check for sphinx-build
-ifeq ($(shell which $(SPHINXBUILD) >/dev/null 2>&1; echo $$?), 1)
-$(error The '$(SPHINXBUILD)' command was not found. Make sure you have Sphinx installed, then set the SPHINXBUILD environment variable to point to the full path of the '$(SPHINXBUILD)' executable. Alternatively you can add the directory with the executable to your PATH. If you don't have Sphinx installed, grab it from http://sphinx-doc.org/)
-endif
-
 # Internal variables.
 PAPEROPT_a4     = -D latex_paper_size=a4
 PAPEROPT_letter = -D latex_paper_size=letter

Pipfile

@@ -0,0 +1,17 @@
+[[source]]
+name = "pypi"
+url = "https://pypi.org/simple"
+verify_ssl = true
+
+[dev-packages]
+
+[packages]
+sphinx-php = {git = "https://github.com/fabpot/sphinx-php.git"}
+sphinx-rtd-theme = "==0.1.6"
+sphinxcontrib-spelling = "==4.2.0"
+pyenchant = "~=2.0"
+docutils = "==0.12"
+Sphinx = "~=1.4.0"
+
+[requires]
+python_version = "3.7"

requirements.txt

@@ -1,4 +1,4 @@
-git+https://github.com/fabpot/sphinx-php.git
+git+https://github.com/fabpot/sphinx-php.git#egg=sphinx-php
 sphinx~=1.4.0
 sphinx-rtd-theme==0.1.6
 sphinxcontrib-spelling