Small fixes, document enhancements, and cleanups

1. Remove the Docker-based installation from documents;
2. Clean up the dependencies list;

Change-Id: I748aa2b41302d5d30e5222de04517084aab6bc8f

doc/source/conf.py

@@ -14,7 +14,6 @@
 
 import datetime
 import os
-import re
 import sys
 
 from pbr import version as pbr_ver

doc/source/installation.rst

@@ -10,7 +10,7 @@ There are two ways to install and run VMTP tool. Users of VMTP should use regula
 PyPI based Installation
 -----------------------
 
-PyPI (The Python Package Index) is the offical repository for software in Python. It holds lots of packages, and the installation is relatively easy in only 2 steps.
+PyPI (The Python Package Index) is the official repository for software in Python. It holds lots of packages, and the installation is relatively easy in only 2 steps.
 
 Step 1
 ^^^^^^
@@ -42,6 +42,12 @@ Create a virtual environment for Python, and install VMTP::
     $ pip install vmtp
     $ vmtp -h
 
+**Note:** "A Virtual Environment is a tool to keep the dependencies required by different projects in separate places, by creating virtual Python environments for them." It is optional but recommended. We could use::
+
+    $ sudo pip install vmtp
+
+instead if isolation among multiple Python projects is not needed.
+
 
 .. _git_installation:
 

doc/source/usage.rst

@@ -21,8 +21,6 @@ VMTP Usage
                    [--stop-on-error] [--vm-image-url <url_to_image>]
                    [--test-description <test_description>]
 
-    OpenStack VM Throughput V2.1.4
-    
     optional arguments:
       -h, --help            show this help message and exit
       -c <config_file>, --config <config_file>

vmtp/vmtp.py

@@ -666,7 +666,7 @@ def main():
         return dest_config
 
     logging.basicConfig()
-    parser = argparse.ArgumentParser(description='OpenStack VM Throughput ' + __version__)
+    parser = argparse.ArgumentParser()
 
     parser.add_argument('-c', '--config', dest='config',
                         action='store',
@@ -974,7 +974,10 @@ def main():
     vmtp_instance = None
 
     cred = credentials.Credentials(opts.rc, opts.pwd, opts.no_env)
-    if cred.rc_auth_url:
+    if not cred.rc_auth_url:
+        print 'Error: Cannot read the credentials of the cloud. '
+        sys.exit(1)
+
     if config.debug:
         print 'Using ' + cred.rc_auth_url
     vmtp_instance = VmtpTest(config, cred)