Bugfixes: Error propagation, migrations version fix, no gofmtcheck for pb's

[tyler-smith]

Simple bugfixes

• tx.Commit() returns and error so this should be propagated
• Migrations only use a single bytes for writing the repo version to disk (in ASCII). This means migrations don't work after 9. This should allow a full int
• There is no need to check gofmt'ing on protobuf generated Go code because it shouldn't be changed even if it violates gofmt rules.

[coveralls]

Coverage decreased (-0.008%) to 31.422% when pulling c6c9f06 on TS_bugfixes into 2cf88a7 on master.

[placer14]

GTM