FIX: Database parsing fails if some tokens are not uppercase

[nandiniraja348]

Updated the database string to always be parsed to uppercase. Also passed the test cases mentioned in the issue #359

[codecov]

Codecov Report

Merging #364 (4fed1c1) into develop (e9c5d6d) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff            @@
##           develop     #364   +/-   ##
========================================
  Coverage    89.86%   89.87%           
========================================
  Files           44       44           
  Lines         4341     4345    +4     
========================================
+ Hits          3901     3905    +4     
  Misses         440      440           

Impacted Files	Coverage Δ
pycalphad/io/tdb.py	87.62% <100.00%> (ø)
pycalphad/tests/test_database.py	100.00% <100.00%> (ø)

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[richardotis]

@bocklund Any thoughts on merging this?

[bocklund]

LGTM