Add isUpperCase() and isLowerCase to AbstractCharSequenceAssert

[marceloverdijk]

Summary

Add isUpperCase() and isLowerCase to AbstractCharSequenceAssert.
Just like AbstractCharacterAssert also has these.

Example

assertThat("ABC").isUpperCase(); // --> currently not possible

assertThat('A').isUpperCase(); // --> currently already possible

Java 8 specific ?

• YES : create Pull Request from the master branch
• NO : create Pull Request from the 2.x branch

[joel-costigliola]

Sure no problem.
Do you want to contribute ?

[marceloverdijk]

Yes fine, I will create a PR later.

[marceloverdijk]

Should I take the master branch as basis?

[marceloverdijk]

I created PR #1107 for this.