Added simple tests for vector and solver
Another floating point workaround
Get rid of numpy in vector.py
Added encoding declaration
Fixed __bool__ for Solution() in Python 2.x
Replace scipy with own gaussian_elimination

This (theoretically) means that sgl.solver.solve can now work with any
numeric type, such as decimal.Decimal or fractions.Fraction instead of
just int and float (what scipy supports). Might be slower, but YOLO, we
got more precision!
Removed scipy and numpy from requirements