Convert a string representing a number in E-form to TeX form.
To use in matplotlib, you need to enclose it with $.
Example:
>> from sci2tex import sci2tex
>> print(sci2tex('12.340e+05'))
12.34{\times} 10^{5}
>> print(sci2tex('12.00e-05'))
12{\times} 10^{-5}
>> print(sci2tex('12.00'))
12