corrected some regexs

Before:
````
julia> NONLETTER_REGEX = Regex("[^a-zA-Z\s]", 0)
Regex("[^a-zA-Zs]",0x00000000)

julia> matchall(NONLETTER_REGEX, "aaaa d123 bbb ccc 678 dddd")
11-element Array{SubString{UTF8String},1}:
 " "
 "1"
 "2"
 "3"
 " "
 " "
 " "
 "6"
 "7"
 "8"
 " "

julia> NUMBER_REGEX = Regex("\d+", 0)
Regex("d+",0x00000000)

julia> matchall(NUMBER_REGEX, "sunday 12")
1-element Array{SubString{UTF8String},1}:
 "d"
````

After:
````
julia> NONLETTER_REGEX = Regex("[^a-zA-Z\\s]", 0)
Regex("[^a-zA-Z\\s]",0x00000000)

julia> matchall(NONLETTER_REGEX, "aaaa d123 bbb ccc 678 dddd")
6-element Array{SubString{UTF8String},1}:
 "1"
 "2"
 "3"
 "6"
 "7"
 "8"

julia> NUMBER_REGEX = Regex("\\d+", 0)
Regex("\\d+",0x00000000)

julia> matchall(NUMBER_REGEX, "sunday 12")
1-element Array{SubString{UTF8String},1}:
 "12"
````