Brief audit of `spot.ride`

[deemru]

• [x] LOW: payment count not checked before accessing https://github.com/Tsunami-Exchange/tsunami-contracts/blob/259ed9d413bb83936111f2f238d4cf37b9a07bf2/contracts/ride/spot.ride#L357-L358
• [x] HIGH: white paper conflict https://github.com/Tsunami-Exchange/tsunami-contracts/blob/259ed9d413bb83936111f2f238d4cf37b9a07bf2/contracts/ride/spot.ride#L179-L180 https://github.com/Tsunami-Exchange/tsunami-contracts/blob/259ed9d413bb83936111f2f238d4cf37b9a07bf2/contracts/ride/spot.ride#L186-L187
• [x] LOW: logically reversed order https://github.com/Tsunami-Exchange/tsunami-contracts/blob/259ed9d413bb83936111f2f238d4cf37b9a07bf2/contracts/ride/spot.ride#L376-L377
• [x] LOW: unnecessary check with 0 https://github.com/Tsunami-Exchange/tsunami-contracts/blob/259ed9d413bb83936111f2f238d4cf37b9a07bf2/contracts/ride/spot.ride#L390
• [x] MEDIUM: duplicated calculation of resultTargetAssetAmount https://github.com/Tsunami-Exchange/tsunami-contracts/blob/259ed9d413bb83936111f2f238d4cf37b9a07bf2/contracts/ride/spot.ride#L394
• [x] HIGH: assetId == _targetAsset does not look supported but never checked https://github.com/Tsunami-Exchange/tsunami-contracts/blob/259ed9d413bb83936111f2f238d4cf37b9a07bf2/contracts/ride/spot.ride#L360
• [x] LOW: i.caller != adminAddress() vs isAdmin() https://github.com/Tsunami-Exchange/tsunami-contracts/blob/259ed9d413bb83936111f2f238d4cf37b9a07bf2/contracts/ride/spot.ride#L250 https://github.com/Tsunami-Exchange/tsunami-contracts/blob/259ed9d413bb83936111f2f238d4cf37b9a07bf2/contracts/ride/spot.ride#L264 https://github.com/Tsunami-Exchange/tsunami-contracts/blob/259ed9d413bb83936111f2f238d4cf37b9a07bf2/contracts/ride/spot.ride#L287 https://github.com/Tsunami-Exchange/tsunami-contracts/blob/259ed9d413bb83936111f2f238d4cf37b9a07bf2/contracts/ride/spot.ride#L304 https://github.com/Tsunami-Exchange/tsunami-contracts/blob/259ed9d413bb83936111f2f238d4cf37b9a07bf2/contracts/ride/spot.ride#L320