remove nose dev dep

acme/setup.py

@@ -31,7 +31,7 @@ if sys.version_info < (2, 7):
     ])
 
 dev_extras = [
-    'nose',
+    'pytest',
     'tox',
 ]
 

setup.cfg

@@ -3,9 +3,3 @@ universal = 1
 
 [easy_install]
 zip_ok = false
-
-[nosetests]
-nocapture=1
-cover-package=certbot,acme,certbot_apache,certbot_nginx
-cover-erase=1
-cover-tests=1

setup.py

@@ -67,7 +67,8 @@ dev_extras = [
     'astroid==1.3.5',
     'coverage',
     'ipdb',
-    'nose',
+    'pytest',
+    'pytest-xdist',
     'pylint==1.4.2',  # upstream #248
     'tox',
     'twine',