Typo fixes "tryies", "snaphot", "Retruns"

Misspellings and grammatical errors found in docstrings
of test.py

Change-Id: Id4d548fa4ae00056aca7434b878eaf8eb09333cc
diff --git a/tempest/thirdparty/boto/test.py b/tempest/thirdparty/boto/test.py
index 4bf71f3..f94d880 100644
--- a/tempest/thirdparty/boto/test.py
+++ b/tempest/thirdparty/boto/test.py
@@ -108,8 +108,8 @@
     CODE_RE = '.*'  # regexp makes sense in group match
 
     def match(self, exc):
-        """:returns: Retruns with an error string if not matches,
-               returns with None when matches.
+        """:returns: Returns with an error string if it does not match,
+               returns with None when it matches.
         """
         if not isinstance(exc, exception.BotoServerError):
             return "%r not an BotoServerError instance" % exc
@@ -485,7 +485,7 @@
 
     @classmethod
     def destroy_volume_wait(cls, volume):
-        """Delete volume, tryies to detach first.
+        """Delete volume, tries to detach first.
            Use just for teardown!
         """
         exc_num = 0
@@ -518,7 +518,7 @@
 
     @classmethod
     def destroy_snapshot_wait(cls, snapshot):
-        """delete snaphot, wait until not exists."""
+        """delete snapshot, wait until it ceases to exist."""
         snapshot.delete()
 
         def _update():