Fix setup.py and use of requirements files.

Author: jeking3

Diff for: git/cmd.py

@@ -220,7 +220,8 @@ def refresh(cls, path=None):
             # - a GitCommandNotFound error is spawned by ourselves
             # - a PermissionError is spawned if the git executable provided
             #   cannot be executed for whatever reason
-            exceptions = (GitCommandNotFound, PermissionError)
+            exceptions = (GitCommandNotFound, PermissionError)  # noqa
+            #                           (silence erroneous flake8 F821)
 
         has_git = False
         try:

Diff for: requirements.txt

@@ -1,2 +1 @@
-gitdb>=0.6.4
-ddt>=1.1.1
+gitdb2 (>=2.0.0)

Diff for: setup.py

@@ -19,6 +19,9 @@
 with open('requirements.txt') as reqs_file:
     requirements = reqs_file.read().splitlines()
 
+with open('test-requirements.txt') as reqs_file:
+    test_requirements = reqs_file.read().splitlines()
+
 
 class build_py(_build_py):
 
@@ -62,9 +65,6 @@ def _stamp_version(filename):
     else:
         print("WARNING: Couldn't find version line in file %s" % filename, file=sys.stderr)
 
-
-install_requires = ['gitdb2 >= 2.0.0']
-test_requires = ['ddt>=1.1.1']
 # end
 
 setup(
@@ -81,9 +81,8 @@ def _stamp_version(filename):
     package_dir={'git': 'git'},
     license="BSD License",
     python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*',
-    requires=['gitdb2 (>=2.0.0)'],
-    install_requires=install_requires,
-    test_requirements=test_requires + install_requires,
+    requires=requirements,
+    tests_require=requirements + test_requirements,
     zip_safe=False,
     long_description="""GitPython is a python library used to interact with Git repositories""",
     classifiers=[
@@ -110,6 +109,6 @@ def _stamp_version(filename):
         "Programming Language :: Python :: 3.4",
         "Programming Language :: Python :: 3.5",
         "Programming Language :: Python :: 3.6",
-        "Programming Language :: Python :: 3.7",
+        "Programming Language :: Python :: 3.7"
     ]
 )

Diff for: test-requirements.txt

@@ -1,6 +1,5 @@
--r requirements.txt
-
+ddt>=1.1.1
 coverage
 flake8
 nose
-mock; python_version=='2.7'
+mock; python_version=='2.7'