Release diffviewer 0.1.0

[hadley]

Prepare for release:

• [x] Check that description is informative
• [x] Check licensing of included files
• [x] Need alternative for csv2array (#7)
• [x] devtools::build_readme()
• [x] usethis::use_cran_comments()
• [x] devtools::check(remote = TRUE, manual = TRUE)
• [x] devtools::check_win_devel()
• [x] rhub::check_for_cran()
• [x] Update cran-comments.md
• [x] Review pkgdown reference index for, e.g., missing topics

Submit to CRAN:

• [x] usethis::use_version('minor')
• [x] devtools::submit_cran()
• [x] Approve email

Wait for CRAN...

• [x] Accepted :tada:
• [x] usethis::use_news_md()
• [x] usethis::use_github_release()
• [x] usethis::use_dev_version()
• [x] Update install instructions in README

[hadley]

@jbkunst I just submitted to CRAN, so if you need to make any changes, can you please do so via PR? (I'm submitting this early because the first submission always takes a little longer. My expectation is that we'll probably do a 0.2.0 release as well, but that will be fast because it should go through the CRAN robot).

[hadley]

On CRAN!