Fixup ci isort check.

Review Request #1728 - Created Feb. 6, 2015 and submitted

John Sirois
dturner-tw, lahosken, zundel
The advice to run the isort in fix mode was not properly escaped and the
fix command would actually run inside backticks - this is now fixed.

Additionally moved the formatting checks to run 1st in ci in their own
section.  These checks are fast and folks will want to know about and
correct these errors before running any other part of ci.

 build-support/bin/ | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)
Created a bad sort:
$ git diff
diff --git a/src/python/pants/ b/src/python/pants/
index ab5df55..590c1db 100644
--- a/src/python/pants/
+++ b/src/python/pants/
@@ -5,10 +5,10 @@
 from __future__ import (absolute_import, division, generators, nested_scopes, print_function,
                         unicode_literals, with_statement)
-import os
 import posixpath
 import subprocess
 from contextlib import closing, contextmanager
+import os
 from twitter.common import log
 from twitter.common.collections import OrderedSet

Then ran ci and no fix was attempted and checks ran 1st failing ci very quickly:
$ ./build-support/bin/ 

[== CI BEGINS ==]

[== Checking python code formatting ==]

ERROR: /home/jsirois/dev/3rdparty/jsirois-pants3/src/python/pants/ Imports are incorrectly sorted.

To fix import sort order, run `build-support/bin/ -f`

CI went green here:
Eric Ayers
John Sirois
Larry Hosken
John Sirois
Review request changed

Status: Closed (submitted)