Rest framework (#24)

* Add rest framework for API: First Commit

* modify some shell scripts to make variable references safer; modify some python scripts to reduce the code complexity and cyclomatic complexity of functions.

* Add REST API for some webvirtcloud functions. Instance list/delete/create, compute list/delete/create, storages-network list/retrieve. Add swagger and redoc for API interface

* update requirements

Co-authored-by: herengui <herengui@uniontech.com>

vrtManager/IPy.py

@@ -181,10 +181,7 @@ class IPint(object):
         if isinstance(data, INT_TYPES):
             self.ip = int(data)
             if ipversion == 0:
-                if self.ip <= MAX_IPV4_ADDRESS:
-                    ipversion = 4
-                else:
-                    ipversion = 6
+                ipversion = 4 if self.ip <= MAX_IPV4_ADDRESS else 6
             if ipversion == 4:
                 if self.ip > MAX_IPV4_ADDRESS:
                     raise ValueError("IPv4 Address can't be larger than %x: %x" % (MAX_IPV4_ADDRESS, self.ip))