Create the class Normaliser

In this Issue, a normaliser class is created, that can read and normalise batches of a given csv file.

Create a class with the name Normaliser with the following constructor:

[x] The constructor should take and set the parameters filePath and batchSize for example:

def __init__ (filePath, batchSize):
    self.filePath = filePath`
    self.batchSize = batchSize`
    ....

[x] Remove the definition of the variable batchSize and filePath at findNormaliser and use instead of it the attribute self.batchSize and self.filePath (so there is no need more to pass parameters to the method). Then call the method findNormaliser, take the results min_val, max_val, and mean_val and set them as global attributes. For example:
```
self.min_val,  self.max_val,  self.mean_val  = findNormaliser()
```
[x] Edit the method readAndFilterBatchFromCsv so it dose not take the parameters filePath and batchSize any more and use the global attributes instead. For example self.filePath and self.batchSize.
[x] Edit the method normaliseBatch so it dose not take min_val, max_val, and mean_val anymore and use the global attributes instead.

shairoMt / Anomaly_detection_at_SWaT