streamparse 3.15.1

Fixes

• Make update_virtualenv create virtualenvs as sudo user, and not just when trying to delete them (0250cfa)
• Prevent pip 19.0 from being installed because it breaks --no-cache-dir installs (db26183)
• Prevent virtualenv from downloading pip versions other than what we have pinned (0573bc8)
• Make redis examples work with sparse run again (b61c85d)
• Fix issues where repr(Topology) was always None (fd5b4b6)

Misc.

• Simplify Travis setup (#454)