lazr-restfulclient fails with ImportError: cannot import name 're_slash'

[Sorin Sbarnea]

A new release of httplib2 renamed re_slash to re_unsafe and broke this library. See https://pypi.org/project/httplib2/

There is no re_slash on current httplib2

```
  File ".../site-packages/lazr/restfulclient/_browser.py", line 85, in <module>
    from httplib2 import _md5, re_url_scheme, re_slash
ImportError: cannot import name 're_slash'
Non-zero exit code (2) from test listing.
```

Code should be updated to work with httplib2>=0.12.0

Do we have a CI job that runs on lazr-restfulclient?

I already have the fix done but using bzr to contribute patches seems to be a deal breaker for sending it.

[Ian Wienand (iwienand)]

Sigh ... [1]; I guess it's questionable if this is considered an external interface or not, it's always better to do something like _ prefix things to make it clear though :/

[1] https://github.com/httplib2/httplib2/commit/56b1fa36be8c3f251602b6be8486c7b891085cce