Update Main.cpp

PCA works!

Output:
The principal components of the following dataset
 / 0.0000 \
|  0.0000  |
 \ 0.0000 /

 / 1.0000 \
|  1.0000  |
 \ 1.0000 /

 / 2.0000 \
|  2.0000  |
 \ 2.0000 /

 / 1.1000 \
|  0.9000  |
 \ 1.0000 /

 / 1.2000 \
|  0.8000  |
 \ 1.0010 /

are:
 /  0.5774  0.5773  0.5774 \
|   0.7060 -0.7082  0.0020  |
 \  0.2555 -0.7994  0.5437 /
or, more intuitively scaled:
 /  1.0000  1.0000  1.0000 \
|   1.0000 -1.0031  0.0028  |
 \  0.4699 -1.4702  1.0000 /
tada!