Check weather.py plots

[AlexDo1]

When testing weather.py with the new input data (#85) I noticed some problems with the app:

• annually aggregated plot: RCPs / climate projections are not shown in the second plot:

• parallel coordinates plot: some of the projections still seem off with lowest temperatures occurring during summer months:

• climate indices plot: before climate indices plot is shown, the user has to select a RCP. This is not necessary, as all RCPs are always shown in the plot, selecting a different RCP does not change anything. Additionally, selecting Continue without climate projections breaks the app.
  Furthermore, the red line Mean of rical is not shown in the plot:

[mmaelicke]

To 1:

I would suggest to remove the 'select second station' checkbox altogether. We can implement a similar solution like in the climate explorer. After the user has been guided through the options once, a control will appear to just add more plot instances, without story mode. @mmaelicke will take care of that.

To 2:

That is a data issue. We have to figure out if the app still loads old data or the new data still has some issues. @AlexDo1 can you identify the shifted lines? What is that? @cojacoo are you aware that there are still issues with the data that you are about to solve, or should things be sorted out?

To 3:

@mmaelicke will disable the RCP selection. @cojacoo can you comment the missing line? We have not yet discussed if this plot will be kept. We can also update it to a plotly plot...