Bump golang to 1.7.1
Bump golang to 1.7.1

- Also fixes pip install error by setting `LANG C`:

```
Traceback (most recent call last):
  File "/usr/bin/pip", line 11, in <module>
    sys.exit(main())
  File "/usr/lib/python2.7/dist-packages/pip/__init__.py", line 215, in main
    locale.setlocale(locale.LC_ALL, '')
  File "/usr/lib/python2.7/locale.py", line 581, in setlocale
    return _setlocale(category, locale)
locale.Error: unsupported locale setting
The command '/bin/sh -c apt-get install -y realpath git curl python python-pip python-dateutil python-magic zip jq; apt-get clean; pip install awscli' returned a non-zero code: 1
```

Signed-off-by: Lyle Franklin <lfranklin@pivotal.io>

[#132688473](https://www.pivotaltracker.com/story/show/132688473)

pivotal-golang/s3cli,pivotal-golang/s3cli,pivotal-golang/s3cli,pivotal-golang/s3cli