Remove old excludes

These are detected as errors since the clean up was done[1] in
the requirements repository. Minimum versions are bumped to avoid
installing these known bad versions.

[1] 314734e938f107cbd5ebcc7af4d9167c11347406

Also remove the note about old pip's behavior because resolver in
recent pip does not require specific order.

Change-Id: I04335dd0d06b5c65b805fbb1e0fc0cd1c10a79fb

doc/requirements.txt

@@ -1,4 +1,4 @@
-sphinx>=2.0.0,!=2.1.0 # BSD
+sphinx>=2.1.1 # BSD
 sphinxcontrib-httpdomain>=1.3.0 # BSD
 sphinxcontrib-blockdiag>=1.5.4 # BSD
 reno>=3.1.0 # Apache-2.0

requirements.txt

@@ -2,10 +2,6 @@
 # date but we do not test them so no guarantee of having them all correct. If
 # you find any incorrect lower bounds, let us know or propose a fix.
 
-# The order of packages is significant, because pip processes them in the order
-# of appearance. Changing the order has an impact on the overall integration
-# process, which may cause wedges in the gate later.
-
 xmltodict>=0.13.0 # MIT License
 cachetools>=2.1.0 # MIT License
 cotyledon>=1.3.0 #Apache-2.0

test-requirements.txt

@@ -1,8 +1,4 @@
-# The order of packages is significant, because pip processes them in the order
+coverage>=4.4.1 # Apache-2.0
-# of appearance. Changing the order has an impact on the overall integration
-# process, which may cause wedges in the gate later.
-
-coverage!=4.4,>=4.0 # Apache-2.0
 eventlet>=0.30.1 # MIT
 fixtures>=3.0.0 # Apache-2.0/BSD
 os-win>=3.0.0 # Apache-2.0