N-dimensional integration

New n-dimensional integration routine 'nquad' included in
scipy.integrate.
Added author name
Some code formatting changes
MAINT: less in-place modification
MAINT: less complicated variable args
MAINT: merge two functions
BUG: recursion termination condition
Merge pull request #1 from argriffing/thezealite-master

some nquad changes
Restarting TravisCI
Revert "Restarting TravisCI"

This reverts commit e7194ac9e2cb79e1577fafdddfac828c16702aa4.
Changes from rgommers

DOC: link to numpydoc via a git submodule
BUG: fix nquad issue for depth=1 integration. Add tests against dbl/t…
MAINT: add runtests.py with enhanced feature set

https://github.com/rgommers/scipy/tree/pr-2510-nquad
Added support for reversed ranges and opts

In tplquad, the calling sequence must be
tplquad(f(x,y,z),z0,z1,y0,y1,x0,x1). nquad makes this more natural:
nquad(f(x,y,z),[[x0,x1],[y0,y1],[z0,z1]]).
This commit adds an additional optional argument "reversed", which
reverts the range ordering to that used by tplquad if reversed=True.
Merge branch 'master' of https://github.com/thezealite/scipy

Conflicts:
	scipy/integrate/quadpack.py
	scipy/integrate/tests/test_quadpack.py