Adjust dependency to support termcolor 1.2 #105

Job	Run time
check	29s
format	21s
check-minimal	22s
doc	26s
test (stable, --no-default-features)	28s
test (stable, --no-default-features --features "test")	35s
test (stable, --no-default-features --features "termcolor")	31s
test (stable)	29s
test (stable, --all-features)	34s
test (beta, --no-default-features)	23s
test (beta, --no-default-features --features "test")	24s
test (beta, --no-default-features --features "termcolor")	31s
test (beta)	23s
test (beta, --all-features)	30s
test (nightly, --no-default-features)	31s
test (nightly, --no-default-features --features "test")	27s
test (nightly, --no-default-features --features "termcolor")	28s
test (nightly)	26s
test (nightly, --all-features)	35s
tarpaulin	17s
publish	0s
	9m 10s

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