115 prepare for cran

[kennedymwavu]

closes #115

• use if (interactive()) {} instead of \dontrun {} for function examples
• add examples & return values to all exported functions
• bump pkg version
• fix: use seq_along(x) instead of 1:length(x) to avoid looping when x has length 0. see here.
• update NEWS.md with new features, updates & bug fixes for v2.2.0
• correct moved urls (devOpifex -> ambiorix-web)

we'll merge this once the pkg is accepted on CRAN.

[JohnCoene]

Did we submit to CRAN before merging this? X)

[kennedymwavu]

we submitted this branch. so that in case there are any changes requested by the CRAN team we do them on this PR, and when it's finally accepted we merge.

[kennedymwavu]

these were the issues raised by CRAN:

the latest commits fix the first two issues:

1. print() / cat()
2. writing to the user's home filespace

what i can't find though are instances of the third issue they raised:

Please do not install packages in your functions, examples or vignette.
This can make the functions,examples and cran-check very slow.

@JohnCoene are we forcing any installations anywhere? can't seem to find any.

[JohnCoene]

Maybe they scan for install.package and found it in the docker thing?

[kennedymwavu]

@JohnCoene you can now merge this :)

[JohnCoene]

Nice work mate! Happy to see ambiorix back on CRAN :)