Initial version of pldm-visualization-pdr tool

- The pldmtool for GetPDR command lacks to display all PDRs at
  once. It fetches only one PDR at a time.

- With a lot of sensors/effecters & with a lot of Host FRU pdrs
  coming in due to concurrent maintenance of the system,where
  the fru's are added/removed at runtime, it's really necessary
  to have a full system view.

- The Intent behind this tool is to fire ssh commands to getPDR
  command on BMC and use the obtained json output to parse and to
  construct a tabular summary.

- This tool also parses the entity association PDR's and generates
  a [picture](https://cdn.discordapp.com/attachments/778790638563885086/850269035827298304/entity_association2021-06-04_123122.pdf)
  that explains the entity association hierarchy at any
  given point in time.

Signed-off-by: Manojkiran Eda <manojkiran.eda@gmail.com>
Change-Id: I37c05233cff1574c7f49d68a3388c2b4ed3dc2a7
diff --git a/tools/visualize-pdr/requirements.txt b/tools/visualize-pdr/requirements.txt
new file mode 100644
index 0000000..03ca676
--- /dev/null
+++ b/tools/visualize-pdr/requirements.txt
@@ -0,0 +1,8 @@
+graphviz==0.16
+tabulate==0.8.9
+bcrypt==3.2.0
+cffi==1.14.5
+cryptography==3.4.7
+paramiko==2.7.2
+pycparser==2.20
+pynacl==1.4.0