Invalid Date Birthday crash

[alexstyl]

Description

This PR fixes the IllegalFieldValueException crash thrown when the user tries to create a Birthday on an invalid date. On the Birthday creation screen, when a new month or year is selected, we update the max day of month for the current month.

Crashlytics Log

Fatal Exception: org.joda.time.IllegalFieldValueException: Value 31 for dayOfMonth must be in the range [1,30]
       at org.joda.time.field.FieldUtils.verifyValueBounds(FieldUtils.java:252)
       at org.joda.time.chrono.BasicChronology.getDateMidnightMillis(BasicChronology.java:632)
       at org.joda.time.chrono.BasicChronology.getDateTimeMillis0(BasicChronology.java:186)
       at org.joda.time.chrono.BasicChronology.getDateTimeMillis(BasicChronology.java:160)
       at org.joda.time.chrono.AssembledChronology.getDateTimeMillis(AssembledChronology.java:120)
       at org.joda.time.LocalDate.(LocalDate.java:457)
       at org.joda.time.LocalDate.(LocalDate.java:436)
       at com.alexstyl.specialdates.date.Date.on(Date.java:41)
       at com.alexstyl.specialdates.addevent.ui.BirthdayDatePicker.getDisplayingBirthday(BirthdayDatePicker.java:131)
       at com.alexstyl.specialdates.addevent.BirthdayPickerDialog$1.onClick(BirthdayPickerDialog.java:93)
       at android.support.v7.app.AlertController$ButtonHandler.handleMessage(AlertController.java:157)
       at android.os.Handler.dispatchMessage(Handler.java:102)
       at android.os.Looper.loop(Looper.java:154)
       at android.app.ActivityThread.main(ActivityThread.java:6077)
       at java.lang.reflect.Method.invoke(Method.java)
       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865)
       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)

Tests added

Yes. The Date class now throws an IllegalArgumentException when some invalid date was asked to be created. Tests were added around this case.