You got some defined functions that arent being used (therefore tested if working), for example in index.js, rotl, rotr and endian.
You need to make tests cover exceptions being thrown (haven't found any in any file). since you are using qunit, assert.throws should do it.
On the derive of HDWallet, you are checking for this.priv, but the pub is not being covered (in case priv is false).
None of the base64 functions from convert.js are being covered.
This is what I got so far.
Btw, you should enable issues in your repo (since when you fork on github, it's not enabled by default)
Ouch - I think you should pay pocesar immediately