Add test for Pipfile + Pipfile.lock

We want to use the more specific version, Pipfile.lock, if it is
available. Are we ignoring the Pipfile if it is, as we should?

tests/venv/pipfile/pipfile-lock/Pipfile

@@ -0,0 +1,18 @@
+[[source]]
+url = "https://pypi.python.org/simple"
+verify_ssl = true
+name = "pypi"
+
+[packages]
+numpy = "*"
+
+[dev-packages]
+sympy = "*"
+
+# The Pipfile.lock was generated when the Pipfile looked like this
+# ----------------------------------------------------------------
+# [packages]
+# requests = "*"
+# 
+# [dev-packages]
+# there = "*"

tests/venv/pipfile/pipfile-lock/Pipfile.lock

@@ -0,0 +1,64 @@
+{
+    "_meta": {
+        "hash": {
+            "sha256": "7160786c1e5cc8e9fe3617f458f7b1c2b617fa44b3fe2f927dee99374c3b05bc"
+        },
+        "pipfile-spec": 6,
+        "requires": {},
+        "sources": [
+            {
+                "name": "pypi",
+                "url": "https://pypi.python.org/simple",
+                "verify_ssl": true
+            }
+        ]
+    },
+    "default": {
+        "certifi": {
+            "hashes": [
+                "sha256:59b7658e26ca9c7339e00f8f4636cdfe59d34fa37b9b04f6f9e9926b3cece1a5",
+                "sha256:b26104d6835d1f5e49452a26eb2ff87fe7090b89dfcaee5ea2212697e1e1d7ae"
+            ],
+            "version": "==2019.3.9"
+        },
+        "chardet": {
+            "hashes": [
+                "sha256:84ab92ed1c4d4f16916e05906b6b75a6c0fb5db821cc65e70cbd64a3e2a5eaae",
+                "sha256:fc323ffcaeaed0e0a02bf4d117757b98aed530d9ed4531e3e15460124c106691"
+            ],
+            "version": "==3.0.4"
+        },
+        "idna": {
+            "hashes": [
+                "sha256:c357b3f628cf53ae2c4c05627ecc484553142ca23264e593d327bcde5e9c3407",
+                "sha256:ea8b7f6188e6fa117537c3df7da9fc686d485087abf6ac197f9c46432f7e4a3c"
+            ],
+            "version": "==2.8"
+        },
+        "requests": {
+            "hashes": [
+                "sha256:502a824f31acdacb3a35b6690b5fbf0bc41d63a24a45c4004352b0242707598e",
+                "sha256:7bf2a778576d825600030a110f3c0e3e8edc51dfaafe1c146e39a2027784957b"
+            ],
+            "index": "pypi",
+            "version": "==2.21.0"
+        },
+        "urllib3": {
+            "hashes": [
+                "sha256:4c291ca23bbb55c76518905869ef34bdd5f0e46af7afe6861e8375643ffee1a0",
+                "sha256:9a247273df709c4fedb38c711e44292304f73f39ab01beda9f6b9fc375669ac3"
+            ],
+            "version": "==1.24.2"
+        }
+    },
+    "develop": {
+        "there": {
+            "hashes": [
+                "sha256:812638ab3683286bf677f273dd6658de93ebbc99fb74ef2548dc8c045d34e8a6",
+                "sha256:a65e4b050b14a57ede8bb852c36eb61f0e9d9e1352039d2f9723f8d0601e146a"
+            ],
+            "index": "pypi",
+            "version": "==0.0.9"
+        }
+    }
+}

tests/venv/pipfile/pipfile-lock/README.rst

@@ -0,0 +1,4 @@
+Python - Pipfile + Pipfile.lock
+-------------------------------
+
+We should make ``Pipfile.lock`` take precedence over ``Pipfile``.

tests/venv/pipfile/pipfile-lock/verify

@@ -0,0 +1,3 @@
+#!/usr/bin/env python
+import requests
+import there