Add key word arguments and type hints to TEAPOT node constructors

[austin-hoover]

This PR adds key word arguments and type hints to all TEAPOT node constructors. Addresses Issue #63.

Changes

• Added type hints to all arguments in TEAPOT node constructors in orbit.teapot.teapot.
• Added key word arguments to all TEAPOT node constructors in orbit.teapot.teapot. For example, the kq parameter for QuadTEAPOT is now an argument in the constructor.
• Added tests to /examples/TEAPOT (where should these go?).

Example: FODO lattice

from orbit.teapot import TEAPOT_Lattice
from orbit.teapot import DriftTEAPOT
from orbit.teapot import QuadTEAPOT

length = 5.0
length_quad = 0.25 * length
length_drift = 0.25 * length
kq = 0.65
nparts = 4

Old:

lattice = TEAPOT_Lattice()

node = DriftTEAPOT("drift1")
node.setLength(length_drift * 0.5)
node.setnParts(nparts)
lattice.addNode(node)

node = QuadTEAPOT("quad1")
node.setLength(length_quad)
node.setnParts(nparts)
node.setParam("kq", +kq)
lattice.addNode(node)

node = DriftTEAPOT("drift2")
node.setLength(length_drift)
node.setnParts(nparts)
lattice.addNode(node)

node = QuadTEAPOT("quad2")
node.setLength(length_quad)
node.setnParts(nparts)
node.setParam("kq", -kq)
lattice.addNode(node)

node = DriftTEAPOT("drift3")
node.setLength(length_drift * 0.5)
node.setnParts(nparts)
lattice.addNode(node)

New:

nodes = [
    DriftTEAPOT(length=length_drift * 0.5, nparts=nparts, name="drift1"),
    QuadTEAPOT(length=length_quad, kq=+kq, nparts=nparts, name="quad1"),
    DriftTEAPOT(length=length_drift, nparts=nparts, name="drift2"),
    QuadTEAPOT(length=length_quad, kq=-kq, nparts=nparts, name="quad2"),
    DriftTEAPOT(length=length_drift * 0.5, nparts=nparts, name="drift3"),
]
lattice = TEAPOT_Lattice()
for node in nodes:
    lattice.addNode(node)

[azukov]

Good to go.