Ngram text files not properly referenced when used as a library

[thaliaarchi]

After installing gocipher (via "go get" and "go build"), for it to work, a symlink needs to be created from the ngrams/ dir to the place where the gocipher library is used. This needs to be fixed to not rely on a symlink for portability.

$ go run affinetest.go
panic: error opening file "ngrams/english_1-grams.txt": open ngrams/english_1-grams.txt: no such file or directory

goroutine 1 [running]:
github.com/andrewarchi/gocipher/gocipher.LoadNgrams(0x10de633, 0x7, 0x1, 0x54)
	/Users/kbouley/projects/go/src/github.com/andrewarchi/gocipher/gocipher/ngrams.go:66 +0x9e8
github.com/andrewarchi/gocipher/gocipher.init()
	/Users/kbouley/projects/go/src/github.com/andrewarchi/gocipher/gocipher/ngrams.go:12 +0x425
main.init()
	<autogenerated>:1 +0x50
exit status 2

I was kindly notified of this issue by Kris Boulez.