revert span/trace id generation (#1470)

Author: Kyle-Verhoog

ddtrace/span.py

@@ -3,7 +3,7 @@
 import traceback
 
 from .vendor import six
-from .compat import StringIO, stringify, iteritems, numeric_types, time_ns, is_integer
+from .compat import StringIO, stringify, iteritems, numeric_types, time_ns, is_integer, getrandbits
 from .constants import (
     NUMERIC_TAGS,
     MANUAL_DROP_KEY,
@@ -15,7 +15,6 @@
 )
 from .ext import SpanTypes, errors, priority, net, http
 from .internal.logger import get_logger
-from .internal import _rand
 
 log = get_logger(__name__)
 
@@ -93,8 +92,8 @@ def __init__(
         self.duration_ns = None
 
         # tracing
-        self.trace_id = trace_id or _rand.rand64bits()
-        self.span_id = span_id or _rand.rand64bits()
+        self.trace_id = trace_id or getrandbits(64)
+        self.span_id = span_id or getrandbits(64)
         self.parent_id = parent_id
         self.tracer = tracer