Remove misleading code comment from docs

In the Specifying Versions section of the Basics documentation, there is
a misleading code comment saying that requests~=1.2 is equivalent to
requests~=1.2.0, which it isn’t. ~=1.2 is equivalent to >=1.2,<2.0, but
~=1.2.0 is equivalent to >=1.2.0,<1.3. Fixed by removing the comment.

docs/basics.rst

@@ -188,7 +188,7 @@ You can specify versions of a package using the `Semantic Versioning scheme <htt
 
 For example, to install requests you can use: ::
 
-    $ pipenv install requests~=1.2   # equivalent to requests~=1.2.0
+    $ pipenv install requests~=1.2
 
 Pipenv will install version ``1.2`` and any minor update, but not ``2.0``.