Pip requirements and fixes.

1) Reduced the flags being sent to pip.
2) Required a minimum of pip 7.0.0 for Home Assistant.

homeassistant/util/package.py

@@ -13,8 +13,7 @@ def install_package(package, upgrade=False, target=None):
     """Install a package on PyPi. Accepts pip compatible package strings.
     Return boolean if install successfull."""
     # Not using 'import pip; pip.main([])' because it breaks the logger
-    args = [sys.executable, '-m', 'pip', 'install', '--quiet',
-            '--isolated', '-I', package]
+    args = [sys.executable, '-m', 'pip', 'install', '--quiet', package]
     if upgrade:
         args.append('--upgrade')
     if target:

requirements.txt

 requests>=2,<3
 pyyaml>=3.11,<4
 pytz>=2015.4
+pip>=7.0.0

requirements_all.txt

@@ -2,6 +2,7 @@
 requests>=2,<3
 pyyaml>=3.11,<4
 pytz>=2015.4
+pip>=7.0.0
 
 # Optional, needed for specific components