Update LICENSE (#2754)
Update LICENSE (#2754)

Replacing the contents of the LICENSE file with the exact text of https://www.apache.o…nses/LICENSE-2.0.txt including the APPENDIX.
mark-friedman/blockly,rachel-fenichel/blockly,picklesrus/blockly,rachel-fenichel/blockly,picklesrus/blockly,google/blockly,mark-friedman/blockly,rachel-fenichel/blockly,google/blockly,google/blockly,mark-friedman/blockly,rachel-fenichel/blockly,picklesrus/blockly,mark-friedman/blockly,google/blockly,google/blockly,rachel-fenichel/blockly,google/blockly,google/blockly,mark-friedman/blockly,mark-friedman/blockly,rachel-fenichel/blockly,rachel-fenichel/blockly