Fixed pytest not working with python 2.7. So turning travis tests back on for that version of python.

.travis.yml

@@ -91,7 +91,7 @@ matrix:
 
     ###################
     - language: python
-      python: 3.5
+      python: 2.7
       env:
         - VARIANT=python-api
       script:
@@ -99,7 +99,7 @@ matrix:
 
     ###################
     - language: python
-      python: 3.7
+      python: 3.5
       env:
         - VARIANT=python-api
       script:

setup.py

@@ -230,7 +230,8 @@ setup(
     ext_modules=[CMakeExtension('dlib','tools/python')],
     cmdclass=dict(build_ext=CMakeBuild, test=PyTest),
     zip_safe=False,
-    tests_require=['pytest==3.8'],
+    # We need an older more-itertools version because v6 broke pytest (for everyone, not just dlib)
+    tests_require=['pytest==3.8', 'more-itertools<6.0.0'],
     #install_requires=['cmake'], # removed because the pip cmake package is busted, maybe someday it will be usable.
     packages=['dlib'],
     keywords=['dlib', 'Computer Vision', 'Machine Learning'],