Masters are not accurate enough

If I compare the masters in https://github.com/laerm0/opensans/blob/master/source/OpenSans-Roman.glyphs against the fonts we currently serve, we can see they're different.

_Outline in Blue is from the Bold Variable font instance. Outline in grey is from the Bold we currently serve on Google Fonts. No kerning present in either fonts._

It isn't just the outlines, the glyph's horizontal metrics also differ.

__Bold metric differences__

```
Upsilontonos 1278.0 1565.0
uni1F4D 1630.0 1712.0
threequarters 1822.0 1804.0
uni0485 0.0 1182.0
Iotatonos 678.0 1049.0
uni0486 0.0 1182.0
uni0512 1526.0 1675.0
Omicrontonos 1630.0 1712.0
uni0513 1321.0 1483.0
IJ 1356.0 1475.0
onehalf 1822.0 1804.0
seveneighths 1822.0 1804.0
circumflex 869.0 1243.0
napostrophe 1606.0 1595.0
uni0483 0.0 1141.0
uni0484 0.0 1182.0
oneeighth 1822.0 1804.0
macron 600.0 1243.0
onequarter 1822.0 1804.0
threeeighths 1822.0 1804.0
equal 1162.0 1169.0
uni0478 2743.0 2701.0
uni0479 2433.0 2345.0
Etatonos 1567.0 1710.0
CR 532.0 1044.0
ij 1250.0 1210.0
fiveeighths 1822.0 1804.0
Epsilontonos 1147.0 1290.0
uni0511 1137.0 1139.0
uni04FC 1366.0 1499.0
uni04FD 1184.0 1321.0
uni04F9 1882.0 1741.0
```

__Light metric differences__

```
uni03D2 1104.0 1081.0
uni03D1 1208.0 1238.0
Upsilontonos 1321.0 1081.0
uni03D6 1587.0 1594.0
uni1F4D 1632.0 1565.0
dotaccent 483.0 389.0
threequarters 1516.0 1592.0
uni0485 1182.0 0.0
Iotatonos 602.0 516.0
uni0486 1182.0 0.0
uni0462 1378.0 1345.0
Omicrontonos 1577.0 1565.0
cedilla 420.0 445.0
hungarumlaut 1182.0 1162.0
uni0463 1241.0 1195.0
ring 1182.0 4.0
tonos 1182.0 1123.0
onehalf 1516.0 1592.0
grave 1182.0 9.0
seveneighths 1516.0 1592.0
circumflex 1182.0 582.0
uni0483 1141.0 0.0
uni0484 1182.0 0.0
oneeighth 1516.0 1592.0
uni0489 1958.0 1989.0
uni0488 2025.0 2024.0
macron 1141.0 52.0
onequarter 1516.0 1592.0
threeeighths 1516.0 1592.0
uni02BC 297.0 310.0
uni0472 1565.0 1551.0
uni0473 1200.0 1166.0
uni0474 1210.0 1267.0
uni0475 973.0 1000.0
uni0476 1210.0 1267.0
uni0477 973.0 1000.0
uni0478 2335.0 2337.0
uni0479 2093.0 2140.0
Etatonos 1563.0 1473.0
breve 1182.0 56.0
CR 1044.0 532.0
ij 926.0 889.0
fiveeighths 1516.0 1592.0
Epsilontonos 1221.0 1130.0
uni04E8 1565.0 1551.0
uni04E9 1200.0 1166.0
tilde 1182.0 93.0
uni04BB 1167.0 1208.0
acute 1182.0 9.0
uni01F0 463.0 426.0
uni04EB 1200.0 1166.0
uni04EA 1565.0 1551.0
jcircumflex 463.0 426.0
caron 1182.0 582.0
Omegatonos 1608.0 1587.0
dieresistonos 1182.0 1133.0
uni04FC 1192.0 1102.0
uni04FD 1036.0 1020.0
fraction 246.0 216.0
dieresis 1182.0 1266.0
uni04F9 1481.0 1628.0
j 463.0 426.0
ogonek 356.0 8.0
cyrillichookleft 418.0 348.0
```

Since both the Light and Bold masters have metric issues, the Regular is getting distorted to an unacceptable level.


_Open Sans VF regular instance vs Open Sans Regular on Google Fonts_

For a font which is requested ~27 billion times a week and served on 25 million+ sites, there shouldn't be any document reflow.