Loosen stevedore requirement to avoid conflicts.

Projectfile

@@ -51,7 +51,7 @@ python.add_requirements(
     'psutil >=5.4,<6',
     'python-slugify >=1.2,<1.3',
     'requests >=2,<3',
-    'stevedore >=1.27,<1.28',
+    'stevedore ~=1.27',
     'whistle >=1.0,<1.1',
     dev=[
         'pytest-sugar >=0.9,<0.10',

requirements.txt

@@ -17,7 +17,7 @@ python-slugify==1.2.4
 pytz==2017.3
 requests==2.18.4
 six==1.11.0
-stevedore==1.27.1
+stevedore==1.28.0
 unidecode==0.4.21
 urllib3==1.22
 whistle==1.0.0

setup.py

@@ -61,7 +61,7 @@ setup(
     install_requires=[
         'colorama (>= 0.3)', 'fs (>= 2.0, < 2.1)', 'graphviz (>= 0.8, < 0.9)', 'jinja2 (>= 2.9, < 3)',
         'mondrian (>= 0.6, < 0.7)', 'packaging (>= 16, < 17)', 'psutil (>= 5.4, < 6)', 'python-slugify (>= 1.2, < 1.3)',
-        'requests (>= 2, < 3)', 'stevedore (>= 1.27, < 1.28)', 'whistle (>= 1.0, < 1.1)'
+        'requests (>= 2, < 3)', 'stevedore (~= 1.27)', 'whistle (>= 1.0, < 1.1)'
     ],
     extras_require={
         'dev': [