Remove dplyr as a dependency

[Swarchal]

Causing too many problems, see if it's possible to remove it and just use base R.

Problem 1:

In true tidyverse fashion ggplot2 and dplyr clobber each other's namespaces, causing lots of warnings on load:

1: replacing previous import by ‘ggplot2::quo_name’ when loading ‘platetools’
2: replacing previous import by ‘ggplot2::enquos’ when loading ‘platetools’
3: replacing previous import by ‘ggplot2::vars’ when loading ‘platetools’
...

Could fix this by using importFrom rather than import on either or both dplyr/ggplot2.

Problem 2:

They keep making breaking changes.