Add rbt info command to display review request data

Review Request #10285 — Created Oct. 26, 2018 and updated Oct. 26, 2018, 12:11 p.m.

Information
Owner:	brennie
Repository:	RBTools
Branch:	master
Bugs:
Depends On:
Commit:	97fd42f...
Reviewers
Groups:	rbtools
People:

Description

The rbt info command has been added to show detailed information about
a review request, including its summary, description, and commit
information.

Testing Done

Ran rbt info in the following conditions:

The review request was attachments-only.
No diffset revision was provided.
The requested diffset revision did not exist.
The requested diffset revision did exist.
The review request was created without commit history support.
The review request was created with commit history support.

Issues

Description	From	Last Updated
F821 undefined name 'sumary'	reviewbot	Oct. 26, 2018, 12:10 p.m.
W391 blank line at end of file	reviewbot	Oct. 26, 2018, 12:10 p.m.

flake8 failed.

JSHint passed.

flake8

rbtools/commands/info.py (Diff revision 1)
Show all issues
```
F821 undefined name 'sumary'
```
rbtools/commands/info.py (Diff revision 1)
Show all issues
```
W391 blank line at end of file
```

Commit:

-	f283036e1f611d1d2a1183783896968142697b0b
+	97fd42f134bae4c2df3b076512381a2a7a4aa81d

Diff:

Revision 2 (+98 -1)

Show changes

	setup.py
	rbtools/commands/info.py
	rbtools/commands/status.py

Checks run (2 succeeded)

flake8 passed.