direct_prob_RR: Potential Cyclists (Relative Risk Approach)
In ITHIM/scenic: Generate Scenarios for Cycling Using Travel Survey Data

Identifies IDs of all ppl (including also these who were cyclist already) who became potential cyclist using relative risk approach

1	direct_prob_RR(baselineSubset, DP, ebikes, equity, pcycl_baseline, region)

`baselineSubset`	A subset of baseline travey survey data as a data frame
`DP`	Direct probability of potential cyclists
`ebikes`	Boolean variable for ebikes
`equity`	Boolean variable for equity (between men and women)
`pcycl_baseline`	Cycling probability broken down by age and gender groups
`region`	An integer variable to specify one of the nine regions of England