Merge pull request #1 from cdrv/master

Merging SNAPR functionality
edited readme and desc files
Merge pull request #3 from cdrv/master

str_split --> split_to_df; closes #2
slight edit to readme
added vignette, and small change to NCBI_snp_query to loop through the correct length iterations
bumped version number
added vignette
fix bug in NCBI SNP query; avoid rbinding